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Volume|Issue|Year|Page_Range|Stock_Number|Authors|Title|Keywords|Abstract|IMAGE_PATH|Paper_Type|PUB_ID|PAP_ID|PAP_STOCK|MSBUG|NumPages|OkToPublish|OkForWeb|sLongDate|DOI|DatePublished|Committee|EventID|EventName|EventStartDate|EventEndDate|DateReceived|DateAccepted|ISSN|CommitteeName|User_Pap_Num|Autonum 34|4|2006|1-5|JTE0607|Zhou L, Chen J|Mechanical Principles of a New Two-Way Composite Disk Spring Cap for Pile Driving|two-way composite, disk spring pile cap, mechanical principles, combination mode|
The new two-way composite disk spring pile cap cannot only maintain the quality of construction but also improve pile-driving efficiency because the disk spring has both a high recovery coefficient and a high spring constant. In this paper the structural type, mechanical principles, composite disk spring mode of this kind of pile cap, and its pile-driving mechanism are introduced in detail. The results demonstrate that in order to obtain the optimum effect in pile driving one must properly choose the combination mode and compound stiffness of the composite disk spring.|JTE11962|Technical Note|182006344||JTE11962||5|1|1|2006-07-01 0:00:00|10.1520/JTE11962|2006-03-02 0:00:00||||||2003-05-22 0:00:00|2005-11-15 0:00:00|0090-3973||11962|883 34|5|2006|1-7|JTE0609|Pircher M|Testing of Rock Climbing Anchors|rock climbing anchors, EN959, testing method, strength, repetitive loading|
The testing procedures for small rock anchors for various recreational activities including rock climbing are regulated in the European Standard EN959. This paper reports on the use of this testing method in a recent study on the strength of rock climbing anchors in sandstone with a relatively low compressive strength. Some limitations of this method were identified and modifications were implemented in order to overcome these limitations. The modified testing procedure and some representative test results are summarized.|JTE14117|Journal Article|182006345||JTE14117||7|1|1|2006-09-01 0:00:00|10.1520/JTE14117|2006-03-02 0:00:00||||||2005-03-21 0:00:00|2006-01-25 0:00:00|0090-3973||14117|884 34|3|2006|1-8|JTE0605|Kulkarni SP, Vipulanandan C|Hot Wire Method to Characterize the Thermal Conductivity of Particle-Filled Polymer Grouts Used in Pipe-in-Pipe Application|thermal conductivity, pipe-in-pipe, hot wire method, microspheres, polymer, aggregates|
Insulated flowlines are considered a practical solution to prevent hydrate formation and paraffin deposition during the transportation of unprocessed well fluids to production facilities. A conventional pipe-in-pipe (PIP) system relies mainly on the heat transfer mode based on the thermal conductivity of the insulation material. Hence, in this study, a laboratory procedure was used to determine the thermal conductivity (
The X-ray method is used extensively to determine the residual stress in bulk or thin film materials on the assumptions that the material is composed of fine crystals with random orientation and the stress state is biaxial and homogeneous through the X-ray penetrating region. But the method cannot be used in textured films due to oscillations in ε−sin2 ψ relation. In this paper, a new method is proposed for measuring residual stress in cubic films with any [
The Rockwell hardness (HR) test is a valuable and widely used indentation hardness test for evaluating mechanical properties of metallic materials. For the Rockwell scales that use a ball indenter, either a steel or tungsten carbide (WC) ball indenter is permitted to be used in the current standards of ASTM International and the International Organization for Standardization. However, significant differences occur in Rockwell hardness tests depending on whether the ball indenter that is used is made of steel or WC. In this paper, finite element analysis is used to simulate the HR indentation process using steel and WC ball indenters on the same test materials under the same testing conditions. The effects of four different sizes of steel and WC ball indenters on different Rockwell hardness scales are studied and compared with the experimental tests. This study provides important approximations of differences between the performance of steel and WC Rockwell hardness indenters.|JTE100048|Journal Article|182006343||JTE100048||13|1|1|2006-05-01 0:00:00|10.1520/JTE100048|2006-03-15 0:00:00||||||2005-10-24 0:00:00|2006-01-13 0:00:00|0090-3973||100048|887 34|3|2006|1-7|JTE0605|Cambiaghi D, Magalini A, Ramorino G, Riccò T, Vetturi D|High Frequency Dynamic Testing of Rubbers and Rubber to Metal Devices|rubbers, dynamic behavior, nonlinearity|
This paper develops a methodology to test and evaluate the dynamic properties of elastomeric compounds and of rubber to metal devices by means of an electrodynamic shaker. The dynamic tensile and shear moduli of elastomeric materials and the dynamic stiffness of rubber components are evaluated under different conditions of excitation frequency, temperature, dynamic deformation, and static load.|JTE100121|Journal Article|182006343||JTE100121||7|1|1|2006-05-01 0:00:00|10.1520/JTE100121|2006-03-15 0:00:00||||||2005-09-21 0:00:00|2006-01-12 0:00:00|0090-3973||100121|888 34|3|2006|1-11|JTE0605|Landes JD|Evaluation of the ASTM
The multiple specimen procedure for the evaluation of a
Mechanical properties of transition-induced plasticity steels depend on the possible variations in the complex microstructures, such as the shape, volume fraction, stability, and chemical composition of retained austenite. The effect of retained austenite stability on martensitic transformation is important, and can be evaluated in low strain rate testing conditions by stopping the deformation during testing. However, it is much more difficult to stop the test during a high speed dynamic tensile test. Hence, it was necessary to develop a method to stop a test during high speed deformation. An instrument was designed to attach to the sample to limit the strain during high speed tensile test and the applicability of the system was evaluated over the strain rate range of 10−2 to 102 s−1. This instrument was found to be successful in allowing controlled amounts of tensile strain to be imparted to a specimen under dynamic test conditions.|JTE100073|Technical Note|182006345||JTE100073||4|1|1|2006-09-01 0:00:00|10.1520/JTE100073|2006-03-22 0:00:00||||||2005-12-01 0:00:00|2006-01-13 0:00:00|0090-3973||100073|890 34|5|2006|1-6|JTE0609|Seif MA, Rawwash M|Surface Roughness Measurement Using Laser Speckle Statistical Analysis|laser speckles, variogram analysis, surface roughness, correlation analysis, spatial data analysis|
This work represents a noncontact nondestructive technique for surface roughness measurement. The technique is based on investigating the statistical properties of the speckle patterns that are developed whenever a surface is illuminated with a highly coherent light source such as a laser. The main objective is to correlate the sizes of the speckles with their light intensities to the surface roughness and profile. Different statistical approaches and correlation analysis have been implemented. Spatial data analysis, or variogram analysis, has been used to develop the relationship between observations taken at various locations. Among the other advantages of such an approach, this technique is simple to implement and suitable for operation in a manufacturing environment.
The dynamic behavior of cushioning materials such as hardwood, particle board, pinewood, asbestos-rubber board, and disk springs are fully characterized by different experimental methods. These include static elastic modulus by static loading, dynamic elastic modulus by natural frequency using the cantilever method, dynamic stress-strain curve method, dynamic recovery coefficient by normal impact between a spherule and a plate, and the pile-driving test in a sand pit. The experimental results show that the relationships between dynamic stresses and strains of the pinewood and asbestos-rubber board are quite different compared with the static ones and subsequently result in greater elastic modulus and recovery coefficients. In comparison to the minor effect on reducing pile-driving stresses of the pile body for pinewood, disk springs are a preferred cushioning material because of their stable dynamic properties that can greatly reduce the driving compressive stresses of the pile body.
An understanding of the limiting stress level for crack initiation and propagation in a fuel cladding material is a fundamental requirement for the development of water reactor clad materials. Conventional tests, in use to evaluate fracture properties, are of limited help, because they are adapted from ASTM standards designed for thick materials, which differ significantly from fuel cladding geometry (small diameter thin-walled tubing). The Internal Conical Mandrel (ICM) test described here is designed to simulate the effect of fuel pellet diametrical increase on a cladding with an existing axial throughwall crack. It consists in forcing a cone, having a tapered increase in diameter, inside the Zircaloy cladding with an initial axial crack. The aim of this work is to quantify the crack initiation and propagation criteria for fuel cladding material. The crack propagation is monitored by a video system for obtaining crack extension Δ
A test method for the evaluation of the adhesive strength of coatings of thickness less than 250 μms has been attempted on coupons of pure alumina and alumina-13 wt % titania samples plasma sprayed on low alloy steel substrates. Crosshatches were made with a diamond tipped wheel with 0.02-mm width and 20-mm bore diameter, which was mounted on a common tooling and grinding machine. Cuts with 5×5 mm were made on the as-sprayed surface; subsequently, a pressure-sensitive tape was applied on the hatched surface and pulled off. The area of the coatings thus removed was interpreted in accordance with ASTM D 3359B testing standard; the testing method seems to be appropriate for qualitative evaluations.
This paper presents significant experimental data for hydrophilic characterization of automotive brake fluids. A novel technique is developed for these measurements. Because brake fluid is well known as a hygroscopic fluid, its molecular O–H structure easily allows hydrogen bonding with hydromolecules, e.g., H2O. The moist brake fluid reduces the boiling point and moreover causes the deterioration of the functionality of the brake system. A proximal linear relationship between moisture content and its corresponding resistance for DOT3 brake fluid is found in this study, which uses the signal input of the electronic control unit (ECU) of the brake system. The applied technology of measurement is especially developed in the laboratory, which consists of two functions; the moisture meter and the automatic prewarning system. This instrument changes the controlling conception of a brake system from a passive regular check of brake fluid to an active prewarning for the drivers.
In this paper, cyclic plastic behavior of 316L stainless steel has been investigated through uniaxial experiments. An elasto-plastic material model is proposed that builds on a Chaboche based model that is readily available in commercial FE-software. The model has been calibrated for 316L through cyclic symmetric strain experiments for a strain range up to 4 %. Experiments show that strain loading history and strain range have a significant impact on the behavior of the material. The plasticity model available in FE-codes only depends on the maximum equivalent plastic strain though. More complex material models require a significant number of parameters to be calibrated and require extensive experiments to provide the required calibration data. For most applications this calibration effort is too extensive. To include both phenomena of strain history and strain range dependency, at least in a basic manner, a user subroutine was created that aids the material model in describing these dependencies.|JTE100104|Journal Article|182006344||JTE100104||14|1|1|2006-07-01 0:00:00|10.1520/JTE100104|2006-05-10 0:00:00||||||2005-04-20 0:00:00|2006-03-24 0:00:00|0090-3973||100104|911 34|6|2006|1-8|JTE0611|Edalati K, Rokrok B, Kermani A, Seiedi M, Movafeghi A, Rastkhah N|Sensitivity Evaluation in Double Wall Radiography of Pipes and Multilayer Plates by Assessment the Monte Carlo Simulation|radiography, sensitivity, IQI, scattering, simulation, Monte Carlo, pipe, multilayer plate|
Image quality indicator (IQI) is selected based on the single and/or double wall thickness of pipe with or without considering the radiographic techniques or applied radiation source (x ray or gamma ray), in accordance with the sensitivity requirements of reference codes. Discrepancies in the codes and standards for sensitivity evaluation and IQI selection have been investigated in the present work and some experiments have been performed to measure the gamma ray or x-ray radiographic sensitivity for pipes and plates to compare the results with sensitivity requirements of the standards. Due to the considerable effect of scattering on the sensitivity, Monte Carlo method has also been used to simulate the scattering for gamma ray radiography of pipes and plates. Experiments revealed that 2 % sensitivity based on the single wall thickness was attainable for double wall exposure and single wall viewing (DWSI) technique, but it could not be easily obtained for double wall exposure and double wall viewing (DWDI) gamma ray technique. Higher sensitivity was obtained for x-ray radiography and a considerable sensitivity reduction was found for in-service radiography of pipes. Achieved sensitivities were in good agreement with measured effective attenuation coefficients and simulation results which confirmed that scattering was, respectively, higher for DWDI radiography of pipe, radiography of single layer plate, and DWSI radiography of two layer plate with identical penetrated thickness. Therefore, IQI selection was proposed to be based on the single wall thickness of component except for DWDI Gamma ray radiography, which was proposed to be based on the double wall thickness.|JTE100027|Journal Article|182006346||JTE100027||8|1|1|2006-11-01 0:00:00|10.1520/JTE100027|2006-05-17 0:00:00||||||2005-10-10 0:00:00|2006-04-07 0:00:00|0090-3973||100027|912 34|6|2006|1-10|JTE0611|Kammoun F, Fourati W, Bouhlel MS|Comparative Survey of the DCT and the Wavelet Transforms for Image Compression|wavelet transforms, DCT, entropy encoder, image compression, JPEG, multiresolution analysis|
In the framework of the image compression by transform coding, we studied two transformation techniques, respectively, used in the JPEG and JPEG2000 standards: the discrete cosine transform (DCT) and the wavelets transform (WT). We also studied the influence of different coding techniques on the compression rate. We compare the performances of different wavelets. The set of the techniques that we implemented have been applied on different types of images. We verified the compromise that exists between the compression rate and the quality of the reconstructed image. We noted that when we apply the wavelet transform, we succeeded with best results of those found by the use of the DCT. We note also that the quality of reconstruction is better as we increase the order of the filter associated to the Daubechies wavelets.|JTE100086|Journal Article|182006346||JTE100086||10|1|1|2006-11-01 0:00:00|10.1520/JTE100086|2006-05-17 0:00:00||||||2003-12-01 0:00:00|2006-03-22 0:00:00|0090-3973||100086|913 34|6|2006|1-3|JTE0611|Mesloh CT, Thompson LF|Evaluation of the FN 303 Less Lethal Projectile|less lethal, FN 303, nonlethal, accuracy, projectile|
FN 303 less lethal launcher is at the forefront of less lethal weapons technology and exceeds the standards for accuracy and range. While the manufacturer stated maximum effective range for the FN 303 against a point target is 55 yards (50.29 m), this study found that it was possible to strike a point target at even greater ranges. Additionally, as the projectile descends quickly due to gravity and slowing velocity, an operator cannot rely on sights that are zeroed at 30 yards (27.43 m) to achieve point target strikes at 60 yards (54.86 m) . This study produced a linear model to adjust an operator's point of aim to achieve the desired point of impact. At distances of 40 yards and greater, point of aim should be adjusted 13.7 in. (34.80 cm) for every additional 10 yards (9.14 m) of distance between shooter and target.|JTE100134|Technical Note|182006346||JTE100134||3|1|1|2006-11-01 0:00:00|10.1520/JTE100134|2006-05-17 0:00:00||||||2005-12-06 0:00:00|2006-03-13 0:00:00|0090-3973||100134|914 34|6|2006|1-10|JTE0611|Lee Y, Lu M|Damage-Based Models for Step-Stress Accelerated Life Testing|step-stress accelerated life testing, reliability demonstration test, fatigue life distribution, Weibull distribution, cumulative exposure model, damage curve analysis, double linear damage rule, linear damage rule|
Step-stress accelerated testing of mechanical components offers great potential for improvements in reliability demonstration bench testing. Most mechanical products are designed to operate for a long period of time and in such a case, life testing is a relatively lengthy procedure. Lengthy tests tend to be expensive and the results become available too late to be of much use. To reduce the experimental cost significantly and provide an efficient tool to assess the life distribution for highly reliable products, a step-stress accelerated test was developed. Step-stress testing is achieved by testing the component at stress levels greater than operational levels in a stepwise fashion to reduce the time-to-failure, or life.
Nelson's cumulative exposure model has been widely used to determine the reliability of the test parts under step-stress accelerated testing. The Nelson model does not provide information pertinent to failure mechanism and sites. Further, the model assumes that the previous exposure stress history of a test part is accounted for by the cumulative exposure distribution, instead of the damage curve. Therefore, damage curve analysis (DCA), double linear damage rule (DLDR), and linear damage rule (LDR) are adopted to assess the experimental results from step-stress accelerated testing.
Investigation into Nelson's cumulative exposure model and the three cumulative damage rules to predict fatigue reliability of mechanical products under step-stress accelerated testing was performed. The predictions by Nelson's cumulative exposure model and DCA are better than DLDR and LDR. Due to its simplicity of implementation, LDR is also capable of estimating failure life distribution reasonably well.|JTE100172|Journal Article|182006346||JTE100172||10|1|1|2006-11-01 0:00:00|10.1520/JTE100172|2006-05-17 0:00:00||||||2005-04-04 0:00:00|2006-03-29 0:00:00|0090-3973||100172|915 34|6|2006|1-7|JTE0611|Urbanik TJ, Lee SK, Johnson CG|Column Compression Strength of Tubular Packaging Forms Made from Paper|corner post, compression strength, insert, column buckling|
Tubular packaging forms fabricated and shaped from rolled paper are used as reinforcing corner posts for major appliances packaged in corrugated containers. Tests of column compression strength simulate the expected performance loads from appliances stacked in warehouses. Column strength depends on tube geometry, paper properties, basis weight, and number of laminations. A column strength model considers the tube geometry to be a sequence of geometric flat and arched segments with each segment apt to fail by either buckling or compression. Contributions of segments to strength depend on respective failure modes and are appropriately summed. The principles of our derived model provide insight into the optimum paper properties and number of laminations in the selection and design of tubular posts.|JTE100030|Journal Article|182006346||JTE100030||7|1|1|2006-11-01 0:00:00|10.1520/JTE100030|2006-05-24 0:00:00||||||2005-11-21 0:00:00|2006-03-31 0:00:00|0090-3973||100030|916 34|6|2006|1-6|JTE0611|Zeng M, Huang S|Characterizing the Asphalt-Aggregate Mixtures Using Rheological Properties of Asphalt Binders|asphalt binder, asphalt-aggregate mixture, rheology, viscoelasticity, modeling|
Modeling techniques were employed to establish the relationship between the rheological properties (
Cracks may appear in civil engineering structures, such as buildings, the body of a dam, its galleries, adjoining tunnels, and power plants during or after construction. Swelling or poor soils in the foundations, redistribution of stresses in the tunnels, creep of the materials, earthquakes or other vibrations are just a few reasons for cracks. The relative movements of the walls along and across the crack, and perpendicular to the plane of cracking surface or wall, beyond certain limits, may prove to be damaging. For considerations of safety and maintenance, the measurement of the magnitude and time rate of deformation of the cracks is essential. Instrumentation for deformation monitoring is of vital importance, especially in underground excavations in complex geological formations. A 3D crack monitor is used for 3D crack monitoring. The purpose of this paper is to show that by measuring points along and across a crack the same outcome can be determined with less effort and better precision.|JTE11589|Technical Note|182006345||JTE11589||3|1|1|2006-09-01 0:00:00|10.1520/JTE11589|2006-09-01 0:00:00||||||2002-08-15 0:00:00|2005-10-06 0:00:00|0090-3973||11589|918 34|6|2006|1-5|JTE0611|Bouhlel MS, Kammoun F, Garcia E|An Efficient DCT-Based Cryptocompression Scheme for a Secure and Authentic Medical Image Transmission|cryptocompression, medical image, telediagnostic, DCT, RSA|
The use of telecommunications and information technologies in the medicine domain evolved these last years breathtakingly. This involves the development of the applications bound to the telemedicine. Seeing the importance of this discipline in the improvement of the care quality and in the reduction of treatment costs, the optimization of medical applications performances remains a necessity. In this work, we propose a new and efficient cryptocompression scheme applied to the telediagnostic sector for a secure and authentic medical image transmission. Since only 15 % of discrete cosine transform components are encrypted in our approach, a significant reduction in processing time during the encryption and decryption, without tampering the high compression rate of the compression algorithm, can be performed by the proposed scheme.|JTE100062|Journal Article|182006346||JTE100062||5|1|1|2006-11-01 0:00:00|10.1520/JTE100062|2006-06-14 0:00:00||||||2003-01-13 0:00:00|2006-04-18 0:00:00|0090-3973||100062|919 35|1|2007|1-5|JTE0701|El-Magd E, Gebhard J, Stuhrmann J|Characterization and Simulation of the Creep Behavior of P92 Sandwich Structures at 923 K with Loading Transverse to the Intermediate Layer|creep behavior, sandwich structure, FEM simulation, P92|
Improving thermal efficiency in modern steam turbines can be achieved by the application of new cooling systems, such as sandwich structures which enable cooling steam to flow without severe losses during operation. The mechanical behavior, especially the creep behavior, of the cooling structure could decide its adoption in a newly built combined cycle power plant. P92 sandwich structures which combine an interlayer of a woven wire mesh between two plane sheets were suggested. Creep tests at
The combined bulk specific gravity of aggregates is a basic input in the Superpave asphalt mixture volumetric design. In order to identify and quantify the factors affecting the aggregate specific gravity values, tests methods similar to AASHTO T84 and T85 were conducted on aggregate samples collected from four different quarries in Kansas. All test results were analyzed statistically to find the significance of the factors—top size and fine loss of the aggregates during replicate testing—used in the experimental program. The results show that the bed from which the aggregates are produced has a significant effect on the specific gravities. However, different aggregate products obtained from the same bed in a quarry may have dissimilar specific gravities. The analysis also shows that the aggregate production process affects the specific gravities significantly when the aggregates are softer, such as soft limestone in Kansas. Fine loss during replicate testing does not affect the results for harder aggregates.|JTE100083|Journal Article|182006351||JTE100083||8|1|0|2007-01-01 0:00:00|10.1520/JTE100083|2006-06-14 0:00:00||||||2005-07-01 0:00:00|2006-04-18 0:00:00|0090-3973||100083|921 35|1|2007|1-9|JTE0701|Das S, Cheng JJ, Murray DW|A Test Method to Determine Low-Cycle-Fatigue Behavior of Wrinkled Pipe|test method, wrinkled pipeline, low cycle fatigue, plastic strain reversals, fracture|
Field observations of buried pipelines used by energy industries for transporting natural gas and oil indicate that it is not uncommon for geotechnical movements to impose large displacements on buried pipelines resulting in localized curvature, deformations, and strain in the pipe wall. Often these local deformation results in local buckling in the pipe wall (wrinkling) and, in its post-buckling range of response, wrinkles develop rapidly. Subsequent cyclic load histories may produce cyclic plastic strain reversals in the wrinkle region leading to formation of fractures in the wrinkle region. This paper presents an innovative and simple material test method, called a strip test, which was designed and carried out at the University of Alberta in order to simulate the complicated behavior of pipe wrinkles subject to such low-cycle-fatigue loading. It is found that the strip test is capable of replicating the complicated behavior of wrinkled pipe subject to plastic strain reversals at the wrinkle location due to low-cycle-fatigue loading and provides necessary information that can be used for further studies. For the current project, a total of 16 such strip tests were carried out, and the test data from these strip tests have been used successfully to develop a fracture life assessment (FLA) model for the wrinkled energy pipe subject to strain reversal due to low-cycle-fatigue loading. The development of the FLA model will be presented in a future publication.|JTE100090|Journal Article|182006351||JTE100090||9|1|0|2007-01-01 0:00:00|10.1520/JTE100090|2006-06-14 0:00:00||||||2004-10-19 0:00:00|2006-04-17 0:00:00|0090-3973||100090|922 35|1|2007|1-3|JTE0701|Motola Y, Uzan J|Anisotropy of Field-Compacted Asphalt Concrete Material|asphalt concrete, anisotropy, field-compacted specimen|
This note presents a study to quantify the degree of anisotropy induced in situ by the compaction equipment. Large asphalt concrete samples were cut from the field and sawed in the laboratory to give prismatic specimens
Flexural beam fatigue testing of asphalt mixtures has been used for nearly 40 years in the pavement industry. Since the development of the test, the definitions of initial and failure stifnesses have not been verified or validated in any comprehensive study . The main objective of this study is to validate the criteria used to define the initial and the final stiffnesses in flexure fatigue testing. In this study, extensive flexure fatigue tests were performed on five typical dense-graded mixtures and an asphalt rubber gap-graded mixture. An optimization approach was used, in which different intial and failure conditions were assumed. Fatigue models were developed using linear regression curve fitting and the conditions that produced the best fit were selected. Both the phenomenological and the dissipated energy approaches were used. Test results conclusively indicated that the initial stiffness should be defined at cycle number 50. In addition, when a phenomenological approach for fatigue is employed, the fatigue stiffness should be taken at 50% of the initial stiffness. A stiffness degradation model was developed, which provided an independent proof that failue occurs when the stiffness of the beam is reduced to 50% of the initial stiffness. This model represents a basic material propertey at which damage accumulation in the mixture has produced an inability of the mix to resist further damage independent of the mode of loading. In contract to the tensile strain-failure approach, data analysis with the energy approach showed that fatigue failure stiffness, taken at 30% of the initial stiffness, provided identical fatigue energy failure regardless of constant stress or strain mode of loading. The results show that the phenomenological and energy approaches provide different definition of failure and the test should be consistent with the method of analysis used.|JTE100102|Journal Article|182007351||JTE100102||8|1|0|2007-01-01 0:00:00|10.1520/JTE100102|2006-06-21 0:00:00||||||2005-03-11 0:00:00|2006-04-18 0:00:00|0090-3973||100102|924 35|1|2007|1-9|JTE0701|Wasiuddin NM, Fogle CM, Zaman MM, O'Rear EA|Effect of Antistrip Additives on Surface Free Energy Characteristics of Asphalt Binders for Moisture-Induced Damage Potential|asphalt binder, moisture-induced damage, antistrip additives, surface free energy, dynamic Wilhelmy plate method, contact angle, acid, base|
In this study, the effect of antistrip additives on asphalt binders was evaluated by both laboratory tests and a proposed chemical model of asphalt binder based on the surface free energy characteristics. Two performance graded asphalt binders, namely, PG 64-22 and PG 70-28 and two amine-based liquid antistrip additives, namely, AD-Here HP Plus and Redicote E-6 were evaluated at different percentages (0.25 %, 0.75 %, and 1.5 %). It was found that 1.5 % AD-Here HP Plus and 1.5 % Redicote E-6 increased the total SFE of PG 64-22 by 67 % and 208 %, respectively. Also, the acid components of PG 64-22 and PG 70-28 are 2.9 dyne/cm and 2.5 dyne/cm, respectively, whereas, the corresponding base components are 0.4 dyne/cm for both. With the addition of 1.5 %. Redicote E-6 in PG 64-22, the acid component of the binder reduced by 92 % and the base component of the binder increased by 1141 %.|JTE100290|Journal Article|182007351||JTE100290||9|1|0|2007-01-01 0:00:00|10.1520/JTE100290|2006-07-26 0:00:00||||||2006-01-23 0:00:00|2006-04-18 0:00:00|0090-3973||100290|939 35|2|2007|1-6|JTE0703|Zhang B, Masmoudi R, Benmokrane B|New Method for Testing Fiber-reinforced Polymer Rods Under Flexure|fiber-reinforced polymer (FRP), flexural strength, modulus of elasticity, rod|
This paper provides a new test method to determine the flexural properties of FRP reinforcing rods for material specifications, research and development, quality assurance, and structural design and analysis. This test method specifies the requirements of four-point flexural tests on FRP rods used in place of steel reinforcement or prestressing tendon in concrete on the basis of the knowledge gained from research results. This test method follows the ASTM standard test methods with some modifications according to the intended purpose and easy realization of the tests. Furthermore, flexural verification tests have been conducted on six sizes of diameters of GFRP rods, from #3 to #8 and each having six specimens. The test results were discussed and compared with that obtained from the three-point flexural tests as specified by the ASTM standard test method for flexural properties of fiber reinforced pultruded plastic rods.|JTE100329|Journal Article|182007352||JTE100329||6|1|0|2007-03-01 0:00:00|10.1520/JTE100329|2006-07-26 0:00:00||||||2004-03-26 0:00:00|2006-06-02 0:00:00|0090-3973||100329|940 35|2|2007|1-9|JTE0703|Chen DH, Scullion T|Using Nondestructive Testing Technologies to Assist in Selecting the Optimal Pavement Rehabilitation Strategy|nondestructive testing, Ground Penetrating Radar (GPR), rehabilitation strategy, Falling Weight Deflectometer|
A comprehensive evaluation of pavement condition and an understanding of the underlying causes of pavement distress is vital in selecting the optimal rehabilitation strategy. Three projects were investigated in this study to demonstrate the application of nondestructive testing technologies in this selection process. Ground Penetrating Radar (GPR), Falling Weight Deflectometer (FWD), and Dynamic Cone Penetrometers (DCP) were successfully used on these TxDOT projects. GPR was employed successfully to locate defects in the hot mix surface layer that were responsible for the chronic distress on US 69. This roadway was rehabilitated previously but the strategy used had not addressed the root cause of the pavement problem. FWD and DCP data were also used to determine the structural capacity or layer moduli of the pavement system that allows the designer to derive the overlay thickness. Coring and trenching were utilized to verify the defects detected in the GPR data. The advantage of nondestructive testing is that it provides a comprehensive evaluation of subsurface conditions throughout the entire project, not only at locations where coring and trenching are performed. Furthermore, GPR was employed to verify a rehab design of an old JCP pavement on SH 73. Originally, the plan called for pressure grouting to fill the subsurface voids. However, GPR found no voids under the JCP slab; this was validated in subsequent coring. Therefore the GPR results helped district personnel to eliminate the cost of the pressure grouting. For comparison purposes, GPR results from IH 45 and US 82 (where there were voids under JCP slabs) were utilized.|JTE100136|Journal Article|182007352||JTE100136||9|1|0|2007-03-01 0:00:00|10.1520/JTE100136|2006-08-09 0:00:00||||||2005-06-07 0:00:00|2006-06-01 0:00:00|0090-3973||100136|941 35|2|2007|1-9|JTE0703|Dilek U, Leming ML|Deicer Salt Scaling Resistance of Concrete Containing Manufactured Sands|deicer salt scaling resistance, salt scaling, manufactured sand, pavements, manufactured fine aggregate, frost durability, angularity, fines content, rock dust, air content, mineral admixtures, blended sands|
Manufactured sands are produced by crushing rock deposits to produce a fine aggregate which is generally more angular and has a rougher surface texture than naturally weathered sand particles. Manufactured sands can also contain significant quantities of rock dust. As natural sand deposits become depleted near some areas of metropolitan growth, the use of manufactured sands as a replacement fine aggregate in concrete is receiving attention.
Designers, specifiers, contractors, and material suppliers need to understand the effects of manufactured sand particle shape characteristics and angularity as well as fines content on concrete water demand and concrete durability, including the effects of interrelationships between manufactured sand characteristics.
As part of a comprehensive research program, manufactured sand properties and their effects on fresh concrete properties, mechanical properties and concrete durability were investigated.
Concrete containing commercially available manufactured sands with a wide range of particle angularities and fines contents were included in the laboratory testing program on deicer salt scaling. Angularity of particles and quantity of fines were found to contribute to salt scaling.|JTE100475|Journal Article|182007352||JTE100475||9|1|0|2007-03-01 0:00:00|10.1520/JTE100475|2006-08-23 0:00:00||||||2005-02-16 0:00:00|2006-06-06 0:00:00|0090-3973||100475|942 35|2|2007|1-6|JTE0703|Shindo Y, Shindo I, Narita F|Effect of Magnetic Field on Fatigue Crack Propagation of Single-Edge Cracked Soft Ferromagnetic Specimens under Mode I Loading|elasticity, magnetoelastic analysis, material testing, scanning electron microscopy, soft ferromagnetic materials, fatigue, crack growth|
The purpose of this paper is to investigate the effect of magnetic field on the fatigue crack growth behavior of nickel iron soft ferromagnetic materials under Mode I loading. Fatigue crack growth tests were conducted using single-edge cracked tension specimens in a magnetic field, and the effects of magnetic field and loading condition on the crack growth rates were examined. Magnetic field effect on the stress intensity factor range also was discussed for a single-edge cracked soft ferromagnetic strip. The fracture surfaces were examined by scanning electron microscopy to correlate with fatigue characteristics.|JTE100622|Journal Article|182006352||JTE100622||6|1|0|2007-03-01 0:00:00|10.1520/JTE100622|2006-08-23 0:00:00||||||2006-04-22 0:00:00|2006-06-29 0:00:00|0090-3973||100622|943 35|2|2007|1-5|JTE0703|Ulugergerli EU, Uyanik O|Statistical Correlations Between Seismic Wave Velocities and SPT Blow Counts and the Relative Density of Soils|SPT, seismic velocities, density, P-wave, S-wave|
The relation between seismic P and S-wave velocities, standard penetration test blow counts (SPT-N) and relative density are the subject of our research. We focused especially on variations of SPT-N versus seismic velocities and relative density versus seismic velocities. Contrary to the traditional approach, the scattered nature of the graphs led us to define the empirical relations as upper and lower bounds instead of single average curves. The values, calculated from the upper and lower limits, have large ranges and, therefore, span whole observable values of the site and geological unit. The wideness of the range between the upper and lower limit recommends that if a geotechnical parameter is required for the assessment of the soil condition; direct gathering from the field or core sample must be employed for a realistic evaluation.|JTE100159|Journal Article|182007352||JTE100159||5|1|0|2007-03-01 0:00:00|10.1520/JTE100159|2006-08-30 0:00:00||||||2004-12-06 0:00:00|2006-06-28 0:00:00|0090-3973||100159|944 35|2|2007|1-7|JTE0703|Rao BH, Dalinaidu A, Singh DN|Accelerated Diffusion Test on the Intact Rock Mass|contaminant transport, diffusion, accelerated tests, intact rock mass, electric field|
Contaminant transport through intact rock mass is predominantly diffusive and its modeling using the conventional laboratory tests is extremely time consuming. In addition, maintaining constant ambient conditions over a long duration is difficult and practically impossible. This necessitates modification of the conventional laboratory diffusion experiments so that the diffusion of ions through the intact rock mass is accelerated. To achieve this, researchers have employed an electric field across the samples of concrete and clays. However, the influence of the applied electric field on diffusion characteristics of the intact rock mass has not been studied in detail. With this in view, diffusion tests were conducted on the samples of chalk and sandstone by applying electric fields of different strength. Details of the testing methodology are presented in this paper. Efforts were also made to study the influence of the applied electric field on diffusion characteristics of these rocks.|JTE100184|Journal Article|182007352||JTE100184||7|1|0|2007-03-01 0:00:00|10.1520/JTE100184|2006-08-30 0:00:00||||||2005-05-27 0:00:00|2006-06-19 0:00:00|0090-3973||100184|945 35|2|2007|1-11|JTE0703|Noda N, Liang B|Stress Intensity Formulas for Three-dimensional Cracks in the Vicinity of an Interface|fracture mechanics, stress intensity factor, bimaterial interface, crack|
In this study, stress intensity formulas are considered in terms of the square root of
The most important properties usually measured for refractories are working temperature and thermal stability. Thermal stability of the alumina based samples was measured using standard laboratory procedure, water quench test (JUS.B.D.8.319). The ImagePro Plus program was used for image analysis of deterioration monitoring of the samples before, during, and after water quench test. Mechanical characteristics were considered such as strength, dynamic modulus of elasticity resulting from resonance frequency measurements, as well as ultrasonic velocity. In this work correlation between deterioration, ultrasonic vtelosity, and strength on thermal stability of the samples were investigated. The results were used for validation of the model for the thermal stability behavior prediction of the refractory.|JTE100047|Journal Article|182006346||JTE100047||4|1|1|2006-11-01 0:00:00|10.1520/JTE100047|2006-09-13 0:00:00||||||2005-11-09 0:00:00|2006-05-01 0:00:00|0090-3973||100047|947 34|6|2006|1-8|JTE0611|Hafez Haghighat SM, Taheri AK|Evaluation of the Simulated Material Microstructures Using the Image Processing and Image Analyzing Methods|image processing, image analyzing, simulated microstructure|
With the development of computing systems for data processing, the image processing and image analyzing methods have been developed on the basis of pixel assessment. These methods can analyze and detect the images by assigning a value for each pixel and using the matrices calculations. In the present research, two methods have been used to assess the simulated material microstructures. In the first method, the vertices of the microstructure are counted to determine accurately the mean grain size by the Euler's relationship, while in the second method, the image processing and image analyzing methods are utilized to assess the microstructure image. To verify the accuracies of the methods their results were compared with the experimental results achieved using the standard Heyn intercept method. It was found that in comparison with the common grain size measurement, the image processing method presents a higher accuracy compared with the Eulers's relationship. More information about the microstructure properties such as the mean grain size and the size of the largest grain in the presence of second phase particles are evaluated.|JTE100143|Journal Article|182006346||JTE100143||8|1|1|2006-11-01 0:00:00|10.1520/JTE100143|2006-09-13 0:00:00||||||2004-06-13 0:00:00|2006-06-19 0:00:00|0090-3973||100143|948 35|2|2007|1-9|JTE0703|Silva A, Gartner BL, Morrell JJ|Towards the Development of Accelerated Methods for Assessing the Durability of Wood Plastic Composites|wood plastic composite (WPC), maple, pine, high-density polyethylene, white rot, brown rot, Gloeophyllum trabeum, Postia placenta, Trametes versicolor|
While wood plastic composites have gained an increasingly large share of the market for decks and other outdoor structures, there are many questions about the long-term potential for biodeterioration of these materials. While the plastic does appear to retard moisture uptake, thereby slowing the rate of degradation, a number of laboratory and field studies have found that fungal attack can occur. One approach to addressing this issue is to alter the WPC by either adding biocides or altering structure to retard fungal attack; however, assessing the durability of these new materials poses a challenge because of the lack of standard methods for accelerating the decay. In this study, we explored the use of agar, soil, vermiculite, and liquid media for accelerating the decay rates of pine and maple based WPCs under laboratory conditions. Agar and soil proved to be the most effective substrates, although the agar systems were far easier to prepare, but the degree of fungal attack was a function of moisture uptake. Thicker samples, which tended to absorb moisture more slowly, tended to have sharply lower weight losses. Maple WPCs tended to be more susceptible to fungal attack than those made with pine, suggesting that altering the wood source could be one simple method for enhancing durability without supplemental biocides.|JTE100168|Journal Article|182007352||JTE100168||9|1|0|2007-03-01 0:00:00|10.1520/JTE100168|2006-09-13 0:00:00||||||2005-03-08 0:00:00|2006-06-05 0:00:00|0090-3973||100168|949 35|2|2007|1-9|JTE0703|Lee K, Kim H, Kim N, Kim Y|Dynamic Modulus of Asphalt Mixtures for Development of Korean Pavement Design Guide|asphalt mixture, dynamic modulus, master curve, phase angle, sigmoidal function|
This paper presents the dynamic modulus of asphalt mixtures with granite aggregate which are highly common in Korea. Dynamic modulus was determined by the simplified master curve using test data covering a large range of temperatures from −10°C to 55°C. Four different asphalt mixtures were evaluated in this paper. Four specimens were chosen to evaluate mixtures with two different aggregates (13 mm, 19 mm) except for two different asphalt binders (PG 58-22, PG 64-16). In addition, the mixture was controlled air void (2, 4, 6 %) and asphalt content based on optimum asphalt binder by a Superpave gyratory compactor. It adopts sigmoidal function and compressive dynamic modulus test data obtained at a matrix combination of different frequencies and test temperatures. The experimental dynamic modulus values were compared against modulus values obtained from the predictive equations proposed by NCHRP 1-37A MEPDG.|JTE100045|Journal Article|182007352||JTE100045||9|1|0|2007-03-01 0:00:00|10.1520/JTE100045|2006-09-20 0:00:00||||||2005-10-14 0:00:00|2006-06-27 0:00:00|0090-3973||100045|950 35|3|2007|1-11|JTE0705|Samyn P, Van Schepdael L, Leendertz JS, Van Paepegem W, De Baets P, Degrieck J|Short-Beam-Shear Testing of Composite Rings With Variable Cross Section as Representative for Full-scale Delamination|full-scale, small-scale, finite elements, composite, shear|
Carbon fiber reinforced/epoxy (CFR-E) rings are used as radial reinforcement for polymer bearing elements with diameter 249 mm, functioning under 150-MPa contact pressure. Full-scale loading revealed shear failure caused by a critical radial-axial shear stress. This stress, acting in a section of the CFR-E ring under nonhydrostatic conditions, should be representatively simulated on small-scale short-beam-shear tests. Finite element analysis will be used for verification of a small-scale stress failure criterion. A standard sample geometry could not be applied as the reinforcing ring contains machined edges leading to stress concentrations. A nonhydrostatic stress condition similar to full-scale tests should be simulated in the center of the small-scale beam. Therefore, the effects of various loading conditions and testing parameters such as cross-sectional geometry, beam support and span, beam curvature, and convex/concave loading are investigated. It is concluded that curved beams are preferred over flat geometries and convex loading is preferred above concave loading since it induces a nonhydrostatic stress situation identical to full-scale tests. During small-scale testing of nonrectangular ring sections, an asymmetric stress distribution near the machined edge is representatively simulated. Experimental short-beam-shear tests confirm the influence of the test geometry and a 27-kN equivalent normal load is required for avoiding full-scale fracture.|JTE100089|Journal Article|182006353||JTE100089||11|1|0|2007-05-01 0:00:00|10.1520/JTE100089|2006-10-11 0:00:00||||||2005-09-19 0:00:00|2006-08-03 0:00:00|0090-3973||100089|951 35|3|2007|1-9|JTE0705|Džugan J, Viehrig H|Crack Initiation Determination for Three-Point-Bend Specimens|fracture toughness, crack initiation, blunting line, compliance|
The paper deals with the determination of crack initiation for three-point-bend specimens during fracture toughness testing of materials in the upper transition and upper shelf region. In the presented study various published methods such as the Double Clip Gage Method, the Strain Near to Crack Tip Measurement method, the Double Displacement Method, the Compliance Changing Rate Method, and the Stretch Width Zone measurement were applied together with the methods using the crack extension versus crack mouth opening displacement and force versus displacement for the crack initiation determination. Blunting line based evaluation were also performed and all results were compared. The investigation was carried out on five different steels.|JTE12611|Journal Article|182006353||JTE12611||9|1|0|2007-05-01 0:00:00|10.1520/JTE12611|2006-10-11 0:00:00||||||2004-03-23 0:00:00|2006-02-17 0:00:00|0090-3973||12611|952 34|5|2006|1-7|JTE0609|Chen J, Chang M, Lin K|Device Harmonization to Determine Smoothness Specification for Asphalt Pavements|acceptance smoothness level, device harmonization, smoothness specification|
Pavement smoothness is a key factor in determining highway user satisfaction. Because of technical limitations of traditional equipment and measurement procedures, the adequacy of a straightedge in characterizing roughness and having it relate to user response has come to question. One barrier to more widespread implementation of a new smoothness standard is the lack of objective, verifiable correlation methods for use in establishing specification limits. The purpose of this study was to (1) develop statistical approaches to harmonize two different measurement devices, i.e., a 3-m straightedge and an inertial profiler; and (2) determine the specification for flexible pavements. The device harmonization requires the development of procedures for statistically testing through comparisons to reference measurements. Data collected from 85 pavement sections on newly constructed and resurfaced highways were examined to demonstrate the device's ability to measure specific smoothness properties. Smoothness data are shown to be normally distributed according to the chi-squared test. Test results obtained from straightedge are found to be significantly different from those from profiler. Smoothness specifications applied for straightedge cannot be directly used to those for profiler. A conversion equation is developed to help contractors convert smoothness measurements between these two devices based on the same acceptance level. The International Roughness Index (IRI) obtained from the profiler appears to provide better measures of smoothness and better correlation with user response. Four following ranges are proposed for the smoothness specification according to the acceptance smoothness level: bonus, full pay, penalty, and correction. As the acceptance probability sets at 20 %, the bonus threshold value should be less than 1.20 mm and 2.55 m/km for straightedge and profiler, respectively. The acceptance level is found to be below 2.60 mm and 3.60 m/km for straightedge and profiler, respectively. The demarcation line between penalty and correction is drawn at 95 % of the acceptance probability with corresponding values of 3.35 mm and 4.10 m/km for straightedge and profiler, respectively. This research effort has developed a series of relationships between IRI and straightedge that can assist highway agencies in transitioning to IRI smoothness specification for pavements.
Signal processing techniques have been introduced in the past two decades into engineering applications to analyze particle-scale microstructure. In this paper, a different approach of signal processing techniques for the geotechnical engineering application is introduced. The crushing of granular particles was analyzed by using the sound analysis technique during the shear process of granular materials. Sound analysis setup was implemented to direct shear box to analyze the crushing of granular materials under shear loading. The microphone signal by using an Electret Microphone is processed and the signal coming from the microphone was analyzed by using the Fourier Transform method. Although the analysis is very complex, it is believed the information obtained will help in understanding when the crushing process begins and the extent of crushing which will lead to better understanding of granular materials subjected to shear.
The formation mechanism of the factory-roof pattern in a circumferential notched specimen was examined. To achieve observation of the material's cracks internally, plastic material, that was acrylic, was used for the test. Cyclic torsional tests were performed with and without application of static tension. A factory-roof pattern was formed in the fracture surface when cyclic torsion tests were conducted with static tension. Formation of the factory-roof pattern was found to be dependent on testing conditions. When such a pattern was formed, many small cracks were initiated by shear mode, followed by their coalescence. The new cracks' initiation at the front of the shear mode cracks could be one of the reasons for the coalescence. After the coalescence and branching of cracks, the cracks grew under the control of the maximum principal stress criterion. This behavior was examined by direct observation of the cracks. The final fracture pattern showed the initiation of many shear-mode cracks and their succeeding coalescence. From those observations, we considered the formation of a factory-roof pattern model.
It is postulated that initial crack length always affects the critical propagation of a crack, except when absolutely elastic materials are considered. The reason for this statement is explained, and a new fracture mechanics theory is presented and experimentally justified, complementing previous works in which it was partially developed.
The main innovation presented in this paper is a new fracture mechanics method, called "Limit Line Replacement," which is thought to be applicable to any type of structure, provided some experimental verification is made.
This basis of the method consists in the acceptance that the critical crack length of a cracked structure subjected to fatigue always can be obtained experimentally, if the maximum and the minimum fatigue loads are known.
From this critical crack length, the life of a structure can be estimated experimentally if under similar conditions, the number of required cycles is measured.|JTE12660|Journal Article|182006345||JTE12660||7|1|1|2006-09-01 0:00:00|10.1520/JTE12660|2006-04-05 0:00:00||||||2004-06-03 0:00:00|2005-10-13 0:00:00|0090-3973||12660|899 34|2|2006|JTE12696-6|JTE0603|Singh PJ, Mannan SL|Experimental Determination of Fatigue Crack Closure in 316 (N) Weld Using a Global CMOD Method|fatigue crack growth, crack closure, GCMOD, 316 (N) weld, compact tension specimens|
The crack closure phenomenon is important in order to assess the fatigue crack growth. Hence, the accurate measurement of the opening load of the crack is essential for the determination of the effective stress intensity factor range
The main aim of this paper was to evaluate the practical aspects and compare two of the most common machining techniques employed in the crack compliance (incremental slitting) method for the determination of residual stresses, namely wire electrodischarge machining (WEDM) and circular abrasive saws. For the circular saws, the effect of the rotational speed and blade thickness was also evaluated. Results show that the associated level of errors introduced during thin saw machining can be as low as the results obtained by WEDM machining. However, for practical reasons, WEDM machining offers a better control of cut increment length than sawing techniques. Additionally, higher rotational saw speeds are likely to introduce larger errors in strain readings probably due to higher frictional heat and plasticity generation ahead of the slot tip.|JTE12700|Technical Note|182006342||JTE12700||5|1|1|2006-03-01 0:00:00|10.1520/JTE12700|2006-04-05 0:00:00||||||2004-08-10 0:00:00|2005-08-22 0:00:00|0090-3973||12700|901 34|5|2006|1-5|JTE0609|Chiu C, Lee M|Effectiveness of Seal Rejuvenators for Bituminous Pavement Surfaces|seal rejuvenator, bituminous pavement, rotor vapor recovery, viscosity|
This study investigated the effects of applying three different types of rejuvenators on a highly aged parking lot pavement, which had shown some severe raveling. Cores were taken from the pavement before and after the treatments to examine the effects of these treatments. Tests were performed to determine the viscosity of the recovered asphalt binders from different layers of the pavement before and after the treatment. Right before coring, the surface texture and skid resistance were measured to assess whether the treatment had adversely affected the frictional properties of the pavement.|JTE100056|Journal Article|182006345||JTE100056||5|1|1|2006-09-01 0:00:00|10.1520/JTE100056|2006-04-06 0:00:00||||||2005-11-29 0:00:00|2005-12-20 0:00:00|0090-3973||100056|902 34|5|2006|1-5|JTE0609|Chen J, Zhou L|On the Frequency Response of Model Materials in Hydrotechnics|hydrotechnics test, model material, frequency response, modal dynamic modulus of elasticity|
The properties of frequency response of five kinds of model materials in hydrotechnics are discussed and analyzed by the static tension test and the dynamic cantilever beam test. The frequency response and the changing of the modal dynamic modulus of elasticity are compared between linear elastic and viscoelastic materials. The results show that the modal dynamic modulus of elasticity for linear elastic material is insensitive to frequency and remains stable, while the modal modulus for viscoelastic material changes obviously with frequency, especially at low frequency, which leads to large simulation errors. In this paper, the line portion of the frequency response curve is suggested to be the working frequency, which can eliminate large simulation errors and result in ideal results.|JTE14012|Journal Article|182006345||JTE14012||5|1|1|2006-09-01 0:00:00|10.1520/JTE14012|2006-04-12 0:00:00||||||2005-01-06 0:00:00|2006-01-26 0:00:00|0090-3973||14012|903 34|6|2006|1-3|JTE0611|Palma ES, Martins MG|Durability Test Analysis in a Passenger Vehicle Damper Spring Tower|damage, fatigue failure, automotive tests, track tests, fatigue life|
The current technology for durability qualification of the damper spring tower component of a passenger vehicle is presented. The methodology was based on durability experiments performed on actual components mounted on a vehicle. Stresses acting on the component were experimentally measured by using rosette strain gages. Durability tests were performed over two different public road surfaces. Fatigue damage assessment was performed and the life of the component was estimated.|JTE100039|Journal Article|182006346||JTE100039||3|1|1|2006-11-01 0:00:00|10.1520/JTE100039|2006-04-19 0:00:00||||||2004-12-06 0:00:00|2006-03-03 0:00:00|0090-3973||100039|905 34|6|2006|1-8|JTE0611|Gopalakrishnan K, Thompson MR, Manik A|Multi-Depth Deflectometer Dynamic Response Measurements under Simulated New Generation Aircraft Gear Loading|new generation aircraft (NGA), multi-depth deflectometer (MDD), NAPTF, flexible airfield pavement, rebound responses|
In this paper, the comparative effect of dual-tridem (Boeing 777) and dual-tandem (Boeing 747) gear trafficking is studied on the Multi-Depth Deflectometer (MDD) responses of two medium-strength subgrade flexible test sections at the National Airport Pavement Test Facility (NAPTF). Using the MDD response-time histories and in-depth displacements obtained under repeated traffic loading, the results were investigated in terms of rebound (recovered) and residual (unrecovered) displacements in the pavement and in the subgrade. The resilient behavior of the NAPTF flexible pavement sections were characterized by analyzing the MDD rebound response data. The results showed that the rebound surface displacements were significantly influenced by changes in asphalt concrete surface layer temperature. Analysis of transverse distributions of MDD rebound surface displacements revealed multiple-wheel load interaction effects. In general both the rebound and residual (and hence the maximum total) displacements are approximately equivalent for both the dual-tridem and dual-tandem gears.|JTE100224|Journal Article|182006346||JTE100224||8|1|1|2006-11-01 0:00:00|10.1520/JTE100224|2006-04-19 0:00:00||||||2006-01-05 0:00:00|2006-03-15 0:00:00|0090-3973||100224|906 34|4|2006|1-6|JTE0607|Hao P, Liu H|Effect of Bitumen Acid Number on Moisture Susceptibility of Asphalt Mixtures|bitumen, aggregate, moisture susceptibility, net adsorption test, bitumen acid number|
The interaction between bitumen and aggregate is a primary determinant of asphalt mixture strength; not only is adhesion between bitumen and aggregate related to the aggregate, but it is also a bitumen property. Three different kinds of test methods are used to evaluate the bitumen aggregate bond: the water immersion test, the electro-optic colorimerty test, and the net adsorption test. Retained Marshall stability and modified Lottman test methods are used to evaluate the moisture damage to asphalt mixtures. The paper analyzes relationships between bitumen acid number and asphalt aggregate mixture performance. The results show that aggregate type has a dominant influence on the bitumen aggregate bond, but bitumen type also has an important influence on asphalt mixture performance. When the bitumen acid number is higher, the asphalt mixture is more resistant to moisture damage. The net adsorption test is a better method to evaluate the bitumen aggregate bond; the bitumen acid number can be used to evaluate moisture susceptibility with different bitumens.|JTE14080|Journal Article|182006344||JTE14080||6|1|1|2006-07-01 0:00:00|10.1520/JTE14080|2006-04-19 0:00:00||||||2005-02-15 0:00:00|2005-10-13 0:00:00|0090-3973||14080|907 34|6|2006|1-7|JTE0611|Auras R, Singh SP, Singh J|Performance Evaluation of PLA against Existing PET and PS Containers|Poly(lactide), biopolymers, compatibility, chemical interaction, sustainability|
Poly(lactide) (PLA) polymers are environmentally-friendly biodegradable materials that have garnered growing attention in the past few years as food packaging materials since packages made from PLA have the advantage of being produced from renewable resources, provides significant energy savings, and can be recyclable and compostable. PLA's optical, physical, and mechanical properties have been compared to those of polystyrene (PS) and polyethylene terephthalate (PET) although studies comparing and showing the actual performance of PLA, PS, and PET packages are scarce. The purpose of this study was to investigate and to compare the role of PLA for the food service industry. Two of the commonly used materials to make containers to package fresh food, PET and oriented polystyrene (OPS), were compared with oriented PLA (OPLA). This study involved a number of tests to quantify the physical, mechanical, barrier, and compatibility properties that would affect the selection criteria for containers to be used for food service applications. Based on the results, OPLA, OPS, and PET performances were evaluated. Exposures of the three materials to weak and strong acids for seven days show a minimal reduction in the performance of these polymers. At ambient temperature, PET has the highest impact resistance followed by OPLA and OPS. PET shows the highest oxygen barrier followed by OPLA and OPS. Thus, several of the relevant properties for packaging applications of OPLA are between PET and OPS properties, suggesting that OPLA would also be suitable for some of these applications.|JTE100041|Journal Article|182006346||JTE100041||7|1|1|2006-11-01 0:00:00|10.1520/JTE100041|2006-04-26 0:00:00||||||2004-06-04 0:00:00|2006-02-24 0:00:00|0090-3973||100041|908 34|4|2006|1-7|JTE0607|Chen D, Zhou F, Cortez ER|Determination of Load Damage Relationships through Accelerated Pavement Testing|rutting, load damage exponents, accelerated pavement testing, overload damages|
This paper describes the effects of increased wheel loads on the performance of thin asphalt pavements. Twelve instrumented full-scale test pavements were built inside a temperature/moisture controlled environment, and subjected to accelerated trafficking by means of a Heavy Vehicle Simulator (HVS). The test sections had constant geometry and materials, but the subgrade soil type and moisture content varied. Since tests are in progress, only eight test pavements were used to determine load damage exponents (LDEs). Each test pavement had six test sections for different load levels (22 to 103.5 kN). An LDE model was developed to predict rutting as a function of structural number (SN), load repetitions, and load intensity. Good correlations between the model prediction and measurements were found as at least four test pavements have an R2 value higher than 90 %. Four test pavements had LDEs higher than 7.8, indicating significant impact of loading on rutting performance. It is believed that the high LDEs obtained in this study were attributed to low structural capacity (or structural number, SN) of the test pavements. Thus, it demonstrates that the well known 4th-power law (LDE=4) is too conservative for low SN pavements. With 10 % overloading, 4th-power law will underestimate the damage of these light pavements by approximately 68 % as compared to those from 8th-power law. A general trend was observed, based on available data, for A-2-4 and A-4 soils that LDE increases with increasing moisture content.|JTE100057|Journal Article|182006344||JTE100057||7|1|1|2006-07-01 0:00:00|10.1520/JTE100057|2006-04-26 0:00:00||||||2005-11-16 0:00:00|2006-02-23 0:00:00|0090-3973||100057|909 35|1|2007|1-10|JTE0701|Jadaan OM, Nemeth NN, Segall AE|Time-Dependent Reliability of Thermally Shocked SiC Tubes|probability of failure, Weibull statistics, finite element analysis, fracture mechanics, slow crack growth, CARES/Life, tube|
In real world structural applications, applied thermal and mechanical loads vary with time such as in thermal shock, startup, shut down, and dynamic and vibrational settings. In addition, when a given component is subjected to transient environmental and or thermal conditions, the material properties also vary with time. The objective of this paper is to demonstrate an analytical methodology capable of predicting the transient reliability of components subjected to time-dependent thermomechanical loads taking into account the change in material response with time. Weibull parameters, slow crack growth parameters, as well as the thermal and elastic material properties are allowed to vary with time. In this approach, progressive damage due to slow crack growth is accounted for. This transient reliability capability was added to the NASA CARES/
Many railroads and research institutes have developed nodestructive testing methods in order to prevent accidents and remove the wheels from service before they fail. One of the most promising alternative means of performing this type of inspection is the evaluation of the stress on the forged wheel rim by ultrasonic testing. The main purpose of this test is to detect the wheel rim stress variations. MWL Brasil, with UNICAMP (State University of Campinas)''s support, applied a stress analysis method by ultrasonic test, using longitudinal critically refracted waves (Lcr). The magnitude of stress found was compared with simulation in infinite elements presenting consistent results.|JTE100149|Journal Article|182007351||JTE100149||9|1|0|2007-01-01 0:00:00|10.1520/JTE100149|2006-06-21 0:00:00||||||2004-10-14 0:00:00|2006-04-07 0:00:00|0090-3973||100149|926 35|1|2007|1-10|JTE0701|Petterson KB, Neumeister JM, Strandberg M|V-Notched Shear Specimens for the Inclined Double Notch Shear Test|shear test, interlaminar shear, oblique, notch, V-notch, optimized specimen|
A numerical study of a modified specimen geometry for the inclined double notch shear (IDNS) test was performed. The test uses the standard double notch compression (DNC) specimen whose geometry was modified by replacing the straight grooves with tilted V notches. Arising stress fields were calculated by use of a BEM scheme. Four different geometry parameters were investigated: relative notch distance, specimen loading, and notch tilt and notch opening angles. Different evaluation criteria to determine optimal specimen and test geometries were studied with respect to effects on stress uniformity and stress concentrations/singularities. No single criterion was found to be obviously superior. Judicious specimen loading enabled cancellation of the significant mode I singularity, whereas a careful specimen design enabled the simultaneous cancellation of both modes I and mode II singularities in most specimens. Singular fields (for mathematically sharp notches) were predominant over distances comparable to the root radii used in practice, and thus not very relevant. Further, the shear stress level arising in the specimen center (and in its major part) was controlled by the specimen inclination, whereas stress concentrations in the notch root vicinity were governed mainly by notch tilt and notch opening angles. Appropriately tilted, but sharper notches seemed to result in the generally most uniform stress fields. For the issues studied, several accurate closed form expressions were presented.|JTE100103|Journal Article|182007351||JTE100103||10|1|0|2007-01-01 0:00:00|10.1520/JTE100103|2006-06-28 0:00:00||||||2005-12-05 0:00:00|2006-04-18 0:00:00|0090-3973||100103|927 34|6|2006|1-25|JTE0611|Oh YJ, Hwang IS, Joyce JA|Round Robin Test on Normalization Method under Static Loading Condition|J-R test, normalization method, unloading compliance method, static loading rate, nuclear piping steel|
In 2001, the normalization method was approved as ASTM Method E 1820-01 [1] for use in high loading rate J-R tests. Prior to its approval, High Rate Round Robin was conducted under the coordination of ASTM Subcommittee E08.08.02 for the verification of accuracy and reproducibility of the method. However, the results of the normalization method cannot be verified against those of other well-established methods because no other method is available in the high loading rate condition. In this round robin test, J-R curves were measured under static loading conditions for A106Gr.C nuclear piping steel by the normalization method so that results can be compared with those obtained simultaneously by the unloading compliance method. The deviation of JIc by normalization and differences of JIc values from those of the unloading compliance method were quantified. The normalization method showed JIc deviation up to 60 % when tested with initial a/W=0.5. In order to seek ways to reduce the deviation, both offset method and tangent method were tried for normalization analysis, but with limited improvement. These partially modified normalization methods of the offset method and tangent method decreases the deviation of JIc, but increases the difference from those of the unloading compliance method. More fundamental approaches are warranted for adequate improvement.|JTE100125|Journal Article|182006346||JTE100125||25|1|1|2006-11-01 0:00:00|10.1520/JTE100125|2006-06-28 0:00:00||||||2005-10-31 0:00:00|2006-03-06 0:00:00|0090-3973||100125|928 35|1|2007|1-6|JTE0701|Wainstein JE, Cocco RG, de Vedia LA, Cassanelli AN|Influence of the Calibration Points on the
The present work studies the separability parameter
Information Technology (IT) is the fastest growing technology in the world today. Investment on IT projects in all the sectors of the world economy has been on the increase in the past ten years. This paper proposes 50 performance indices of IT projects and a tool for evaluating them. Some popular IT projects in Nigeria were surveyed by administering questionnaires and holding meetings with their principal actors. The performance indices were subjected to factor analysis by principal components using Statistical Package for Social Scientists (SPSS). Eleven factors were extracted and the percentage contribution of each factor to the success of IT projects was estimated. The total sum of the percentage contributions of all the factors was found to be less than 100. This revealed that there were some extraneous factors whose related performance indices were not considered in the administered questionnaire which were liable to play a significant role in the success of IT projects. Moreover, a factor scores coefficient matrix that can be used to estimate and rank the assessment of each Assessor of IT projects was generated.|JTE100146|Journal Article|182006346||JTE100146||8|1|1|2006-11-01 0:00:00|10.1520/JTE100146|2006-06-28 0:00:00||||||2004-08-31 0:00:00|2006-02-24 0:00:00|0090-3973||100146|930 35|1|2007|1-4|JTE0701|Zelinka SL|Uncertainties in Corrosion Rate Measurements of Fasteners Exposed to Treated Wood at 100 % Relative Humidity|corrosion, exposure test, wood, preservative, ACQ, alkaline copper quaternary|
This paper evaluates the effect that uncertainties in measurements of time, weight, and surface area have on the determination of the corrosion rate of metal fasteners in contact with wood. Three different types of nails were driven into alkaline copper quaternary (ACQ)-treated wood and exposed to 26.7°C (80°C) at 100 % relative humidity environment for up to 1 year. It was observed that uncertainties in measurement of corrosion rate of less than 5 % could be obtained in 6 months of testing. This paper gives a description of the methods used as well as recommendations for future corrosion exposure tests in wood.|JTE100040|Technical Note|182007351||JTE100040||4|1|0|2007-01-01 0:00:00|10.1520/JTE100040|2006-07-12 0:00:00||||||2005-04-11 0:00:00|2006-05-26 0:00:00|0090-3973||100040|931 35|2|2007|1-8|JTE0703|Minak G|Comparison of Different Methods for Fatigue Limit Evaluation by Means of the Monte Carlo Method|fatigue limit, projection methods, staircase, Monte Carlo simulation|
Different methods for the determination of the fatigue or endurance limit of metallic materials are commonly used. They provide different results and it is not possible to know
The authors proposed a practical method for estimating stress fields near a notch in a real structure under in-plane loading in the previous paper. In this method, boundary conditions of a region near a notch are determined reasonably, using the stress field expression and stress components measured by strain gages on the boundary. Therefore, in this method, precise estimation of the stress fields can be performed in a real structure whose boundary conditions are hard to grasp. In this paper, we develop this method further so that it can be used for notches under out-of-plane loading or simultaneous in-plane and out-of-plane loading. A straight boundary near a notch and non-symmetric boundary conditions are investigated as factors lowering the calculation precision. Consequently, there is the angular limitation of a notch in application of this method. However calculation results are accurate enough for most cases.|JTE100142|Journal Article|182007351||JTE100142||10|1|0|2007-01-01 0:00:00|10.1520/JTE100142|2006-07-12 0:00:00||||||2004-02-26 0:00:00|2006-05-25 0:00:00|0090-3973||100142|933 35|1|2007|1-7|JTE0701|Barbuzza RG, Vénere MJ, Clausse A|Quality Assurance of Manufactures by Means of Intelligent Tomographic Processing|inspection, failure analysis, computed tomography, x-ray imaging, nondestructive testing|
Quality standards in industry require highly rapid and reliable inspection tools to optimize the production. In this article, a tomographic technique for defect inspection of manufactures is presented. Previous knowledge of the geometry of the inspected objects is used to shorten the inspection time. The location and dimension of internal defects can be determined rapidly from a few projections, providing valuable data for quality control.|JTE100188|Journal Article|182007351||JTE100188||7|1|0|2007-01-01 0:00:00|10.1520/JTE100188|2006-07-12 0:00:00||||||2005-12-27 0:00:00|2006-05-01 0:00:00|0090-3973||100188|934 31|43|2005|1-6|JTE0505|Tewatia SK, Bose PR|Discussion on "A Study on the Beginning of Secondary Compression of Soils" by R. G. Robinson|||JTE12577|Technical Note|18200631555||JTE12577||6|1|1|2005-05-01 0:00:00|10.1520/JTE12577|2006-07-12 0:00:00||||||2005-07-22 0:00:00|2005-10-06 0:00:00|0090-3973||12577|935 35|2|2007|1-8|JTE0703|Beges G, Stare E, Drnovsek J|Ambiguities in Technical Standards—Case Study IEC 60112—Measuring the Resistance of Solid Isolating Materials to Tracking|standard, test procedure, safety, ambiguity, conformity assessment, IEC 60112|
The paper deals with unclear and incomplete specifications in technical standards and discusses, as a consequence, the ambiguities in specifying testing requirements or even the absence of important facts in the standard. It deals in particular with the technical standard related to the EU Low Voltage Directive (73/23/EEC) for ensuring the safety of electric equipment. These facts are becoming more and more important since the required measurement uncertainty, according to EN ISO/IEC 17025 standard for calibration and testing laboratories is widely implemented and accepted especially with the emerging European and global markets. Placing of products on the market depends on the results of conformity testing against specific characteristics. Therefore, given the importance of standardized test procedures, common understanding of specifications and harmonized interpretation of measuring/testing results is of utmost importance. Regarding measurement/test results, the agreement on influential parameters, contribution to the overall uncertainty is of paramount importance.
The Case study consists of the analyses of IEC 60112 standard: Method for determination of the proof and the comparative tracking indices of solid insulating materials. In the process of uncertainty evaluations, the ambiguity of the standard was identified. This standard describes very complex requirements for tests and is a fine example to highlight the problem.
This article describes problems in connection with indistinctness of the standard IEC 60112.|JTE100028|Journal Article|182007352||JTE100028||8|1|0|2007-03-01 0:00:00|10.1520/JTE100028|2006-07-19 0:00:00||||||2005-10-13 0:00:00|2006-05-31 0:00:00|0090-3973||100028|936 35|1|2007|1-6|JTE0701|Loya JA, Fernández-Sáez J|Dynamic Fracture-Initiation Toughness Determination of Al 7075-T651 Aluminum Alloy|dynamic bending test, dynamic initiation toughness, modified Hopkinson pressure bar, high-speed photography|
We present values of the static and dynamic fracture-initiation toughness at different loading rates of the aluminum alloy Al 7075-T651 obtained on three-point bend specimens with different thicknesses and initial crack lengths. In static conditions, the critical stress intensity factor was measured according to well known procedures. The methodology of dynamic fracture initiation toughness is not yet standardized, and the dynamic tests were done with a modified Hopkinson pressure bar coupled to high-speed cameras to measure the crack mouth opening displacement (CMOD) of the specimens. The critical stress intensity value was obtained from the CMOD at the time that crack starts to grow. This instant was detected by means of crack gauges at the crack tip.|JTE100098|Journal Article|182007351||JTE100098||6|1|0|2007-01-01 0:00:00|10.1520/JTE100098|2006-07-19 0:00:00||||||2005-07-09 0:00:00|2006-04-27 0:00:00|0090-3973||100098|937 35|2|2007|1-10|JTE0703|Pan T, Tutumluer E|Quantification of Coarse Aggregate Surface Texture Using Image Analysis|coarse aggregate, surface texture, image analysis, erosion and dilation|
Aggregate surface texture affects the performance of pavement and railroad track structural layers, such as the unbound aggregate base/ballast, asphalt concrete, and Portland cement concrete. A quantitative surface texture (
Capturing the true cost of wildland fire events is critical for providing a sound basis for public policy. Recently, Lynch [1] suggested additional factors to consider in addition to suppression costs as a means for gaging a fire's total cost. In this study a similar evaluation was done for the second largest fire in Colorado during the 2002 wildland fire season. The Missionary Ridge fire burned 70 475 acres of land in southwestern Colorado in June and July of 2002. Costs associated with the fire were analyzed and separated into three categories: (1) direct costs, (2) rehabilitation costs, and (3) impact costs. Direct costs during the fire were $90 276 323, rehabilitation costs totaled $8 732 608, and impact costs that occurred after fire containment through 2003 amounted to $50 499 849. Impact costs were still accruing at the time this study was completed. In addition, special values were also considered, including the death of a firefighter, wilderness acreage burned, and loss of sensitive species habitat. These costs were estimated to be $3 404 410. The total cost of the fire to date was estimated at $152 803 785 or more than $2168 per acre.|JTE100044|Journal Article|182007352||JTE100044||4|1|0|2007-03-01 0:00:00|10.1520/JTE100044|2007-03-28 0:00:00||||||2005-10-11 0:00:00|2006-07-06 0:00:00|0090-3973||100044|953 35|3|2007|1-5|JTE0705|Bentz DP|Combination of Transient Plane Source and Slug Calorimeter Measurements to Estimate the Thermal Properties of Fire Resistive Materials|building technology, fire resistive material, heat capacity, slug calorimeter, thermal conductivity, transient plane source technique|
The thermal properties of fire resistive materials (FRMs) as a function of temperature critically influence their ability to protect a (steel) structure during a fire exposure. Measurement of these properties is complicated by the microstructural heterogeneity of typical FRMs, the need to measure properties over a wide temperature range from room temperature to 1000°C and higher, and the reactions, phase changes, and volumetric changes that the materials may undergo during exposure to elevated temperatures. This paper presents an integrated approach for determining thermal properties via a combination of two experimental techniques, namely the transient plane source and the slug calorimeter methods. The former is utilized to provide an estimate of the volumetric heat capacity and a room temperature thermal conductivity value for the FRM under study, while the latter is employed to estimate the variation in effective thermal conductivity with temperature, including the influences of reactions and mass transport during multiple heating/cooling cycles. The combination of the two techniques is demonstrated for four different inorganic-based FRMs. Their extension to organic (intumescent) systems is also discussed.|JTE100033|Journal Article|182007353||JTE100033||5|1|0|2007-05-01 0:00:00|10.1520/JTE100033|2006-10-11 0:00:00||||||2005-11-22 0:00:00|2006-08-28 0:00:00|0090-3973||100033|954 35|3|2007|1-8|JTE0705|Pellinen T, Kuczek T|Methodology of Assessing Testing Variation for Volumetric Quantities in Hot Mix Asphalt Production|precision, volumetric quantities, quality assurance, one-sigma limit|
Increasingly, in road construction, pay incentives and disincentives are being related to both the average test results that are obtained during quality assurance testing as well as the variability associated with these values. As a result, state highway agencies must be fully aware of the expected variability that can be associated with each acceptance test since the results will not only be used for acceptance but may be used for pay adjustment also. In this study, a methodology was developed to assess the testing variability in hot-mix asphalt production. The study focused on determining allowable testing variations for the calculated volumetric quantities, including the air voids content and voids in mineral aggregate (VMA) determined from gyratory compacted specimens. A new standard of determining an allowable testing variation for VMA was developed. Furthermore, a test data analysis plan to extract the testing variation from the total measured variation for the hot-mix asphalt quality parameters was developed.|JTE100683|Journal Article|182007353||JTE100683||8|1|0|2007-05-01 0:00:00|10.1520/JTE100683|2006-10-11 0:00:00||||||2006-06-05 0:00:00|2006-08-28 0:00:00|0090-3973||100683|955 35|2|2007|1-10|JTE0703|Bacha A, Feuerstein M, Desrayaud C, Klöcker H|Measuring Stress Strain Curves to Large Strains on Sheet Metal|Large deformation, stress strain curve, aluminium automotive alloy, rolled sheet|
The stress-strain response of aluminium sheet has been determined by a novel plane strain compression test on laminated samples up to equivalent strains of 1.2. The test sample is composed of several sheet layers glued together, machined to shape, and then compressed in a lubricated channel die along the "thin" directions. This simple test has been validated by a comparison of finite element simulations and experimental results. The stress-strain curves can be considered accurate up to strains of 1.2.|JTE100082|Journal Article|182007352||JTE100082||10|1|0|2007-03-01 0:00:00|10.1520/JTE100082|2006-10-18 0:00:00||||||2005-06-09 0:00:00|2006-07-08 0:00:00|0090-3973||100082|956 35|3|2007|1-12|JTE0705|Prakash RV, Shing Shin C|An Evaluation of Stress-Strain Property Prediction by Automated Ball Indentation (ABI) testing|automated ball indentation, spherical indenter, duplex stainless steel, aluminum-copper alloy|
Automated ball-indentation tests were performed on a duplex stainless steel (2205) and on a high-strength Al-Cu alloy (2014-T651) using a tungsten carbide (TC) spherical ball indenter to derive the materials' stress-strain parameters, which were validated with standard tensile specimen data. Test method and data analysis procedures, as proposed by Haggag et al. in a previous research publication, were followed. During analysis, we observed some interesting details, such as the existence of a linear relationship between the maximum applied compressive force and the plastic depth of penetration for a given material, a relationship between force and plastic diameter of indentation, and a unique relationship between plastic diameter of indentation and plastic depth of indentation, which is independent of the material being evaluated. The correlation between ABI derived stress-strain data and tensile stress-strain data was reasonable for duplex stainless steel, whereas the correlation was not good in the case of Al-Cu alloy 2014-T651. This work suggests the need to improve the formulations, taking into account the properties of indenter and indenting material, as well as the need to account for events such as sink-in and pile-up that take place during indentation.|JTE100180|Journal Article|182007353||JTE100180||12|1|0|2007-05-01 0:00:00|10.1520/JTE100180|2006-10-18 0:00:00||||||2005-04-28 0:00:00|2006-08-02 0:00:00|0090-3973||100180|957 35|3|2007|1-7|JTE0705|Shen L, Struble L, Lange D|New Method for Measuring Static Segregation of Self-Consolidating Concrete|segregation, segregation probe, self-consolidating concrete, rheology, robustness|
To study self-consolidating concrete it is important to be able to characterize segregation resistance. In this paper, a segregation probe is introduced as a simple and fast method for testing static segregation of fresh concrete. The results of the segregation probe tests were verified using image analysis. A mechanics analysis was used to estimate the forces acting on the segregation probe and explain why the thickness of a paste/mortar layer at the surface of the concrete can be measured. Finally, use of the probe to determine robustness is presented.|JTE100535|Journal Article|182007353||JTE100535||7|1|0|2007-05-01 0:00:00|10.1520/JTE100535|2006-10-25 0:00:00||||||2006-03-10 0:00:00|2006-09-28 0:00:00|0090-3973||100535|958 35|3|2007|1-6|JTE0705|Jarimopas B, Sayasoonthorn S, Singh SP, Singh J|Test Method to Evaluate Bruising During Impacts to Apples and Compare Cushioning Materials|apple, ballistic pendulum, bruise volume, cushioning, impact energy|
Developing simplified and accurate test methods to quantify and compare performance of impact levels to sensitive produce is a challenge. Despite a variety of packaging options available today, bruising damage is commonplace for post-harvest apples throughout the supply chain. The major sources of bruising are compression, impact, or vibration forces. Understanding where these forces occur can help reduce this type of mechanical damage to apples. The purpose of this study was to investigate the impact characteristics of foam net and corrugated board when applied as wrapping for individual apples. Two grades (count numbers 80 and 100) of "Fuji" cultivar apples imported to Thailand from China were studied. A simple ballistic pendulum test device was developed to measure bruise volume to impact energy relationship. A linear relationship for both types of apples was observed. Bruise volume occurrence probability and impact energy relationship fitted by linear regression were created for cushioned and bare apples. Absorbed energy of various cushioning materials was also calculated under compressive forces.|JTE100584|Journal Article|182007353||JTE100584||6|1|0|2007-05-01 0:00:00|10.1520/JTE100584|2006-10-25 0:00:00||||||2006-04-04 0:00:00|2006-09-28 0:00:00|0090-3973||100584|959 35|1|2007|1-5|JTE0701|Xia Y, Wang Y|Dynamic Testing of Materials with the Rotating Disk Indirect Bar-Bar Tensile Impact Apparatus|split Hopkinson bar, high strain rate, tensile test|
An experimental method is proposed to investigate the tensile behavior of materials at high strain rates by using a developed split Hopkinson tension bar, rotating disk indirect bar-bar tensile impact apparatus. The mechanically-filtered input tensile pulse is generated by incorporating a prefixed metal bar connected between the impact block and the input bar. The pulse amplitude is controlled by the diameter of the prefixed metal bar. The pulse duration is determined by the length of the prefixed metal bar and the velocity of the impact hammer. Dynamic properties of metallic and nonmetallic materials are presented as examples by using this developed rotating disk indirect bar-bar tensile impact apparatus.|JTE100130|Journal Article|182007351||JTE100130||5|1|0|2007-01-01 0:00:00|10.1520/JTE100130|2006-11-01 0:00:00||||||2006-07-30 0:00:00|2006-08-28 0:00:00|0090-3973||100130|960 35|3|2007|1-8|JTE0705|Verdu J, Colin X, Fayolle B, Audouin L|Methodology of Lifetime Prediction in Polymer Aging|polymer aging, lifetime prediction, methodology|
Two approaches for lifetime prediction in polymer aging are compared: the "simulation approach" and the "ideal approach." The widely used "simulation approach," based on the hypotheses which were never clearly formulated, consists of finding a set of exposure conditions such that accelerated aging leads to the same structural states as natural aging. Using simple kinetic models it is demonstrated, that in the general case it is impossible to obtain a "good simulation." Anyhow, in this approach, the problem of the relationship between accelerated aging and natural lifetimes remains unresolved. The "ideal approach" uses nonempirical kinetic models, taking into account structural changes at all the pertinent scales, and also uses polymer physics to establish the link between the polymer structure and the property under consideration. An important characteristic of this approach is that the accelerated aging serves only to determine the model parameters.|JTE100477|Journal Article|182007353||JTE100477||8|1|0|2007-05-01 0:00:00|10.1520/JTE100477|2006-11-01 0:00:00||||||2005-09-05 0:00:00|2006-09-28 0:00:00|0090-3973||100477|961 35|4|2007|1-9|JTE0707|Gopalakrishnan K, Gomez-Ramirez F, Thompson MR|Pavement Deformation Characteristics under Repeated Aircraft Loading with Fixed Wander Sequence|multi-depth deflectometer (MDD), NAPTF, residual responses, permanent deformation, load-path dependency, shakedown|
Full-scale traffic testing was conducted at the Federal Aviation Administration's National Airport Pavement Test Facility (NAPTF) using Boeing 777 (B777) and Boeing 747 (B747) simulated test gears on flexible pavement test sections until they were deemed to be failed. An inertial profiling device was used to measure the transverse surface profiles at frequent intervals during NAPTF trafficking. Results from the multi-depth deflectometers (MDDs) installed within the test pavements were used to monitor the cumulative permanent deformations. The MDD results showed that the sequence of repetitive aircraft gear loads with different wander positions used at NAPTF led to contractive/dilative permanent deformation behavior, especially in the unbound pavement layers. The magnitudes of MDD residual responses were dependent on the position of the traffic gear, the previous traffic history, and the direction of traffic (east/west). These results suggest that reliable prediction of permanent deformation in airport flexible pavements is a highly challenging task owing to the complexities arising from aircraft loading sequence, gear offset and gear offset sequence, and climatic conditions.|JTE100580|Journal Article|182007354||JTE100580||9|1|0|2007-07-01 0:00:00|10.1520/JTE100580|2006-11-15 0:00:00||||||2006-04-03 0:00:00|2006-10-24 0:00:00|0090-3973||100580|962 35|3|2007|1-6|JTE0705|Kang H, Reyes-Villanueva G|Fatigue Prediction of Lightweight Thermoplastic Fiber-Metal Laminates|fatigue, thermoplastic fiber-metal laminate, tensile strength, fatigue prediction|
Lightweight thermoplastic-based fiber-metal laminates were developed based on a self-reinforced polypropylene and a glass fiber-reinforced polypropylene composite material with two sheets of aluminum alloy 2024-T3. The laminates were manufactured using a fast one step cold press manufacturing procedure. The mechanical behavior of the laminates was then investigated under tensile and fatigue loading conditions. The tensile properties of the plain aluminum, the composite materials, and the thermoplastic fiber-metal laminates (TFML) were investigated at quasi-static rates of loading. The fatigue tests were also conducted under load control based on the ASTM E 466 standard procedure. Various loading cycles were employed for the fatigue tests in order to minimize the possibility of heat generation on the composite materials. Three different load levels were applied for the fatigue specimens with zero to max loading. Results have shown that the glass fiber-reinforced polypropylene hybrid systems exhibited higher fatigue strength than the self-reinforced polypropylene based fiber-metal laminates. Following this, a simple prediction method for fatigue life of the TFMLs has been introduced. It is clearly indicated that the stress ranges calculated using the proposed method for the monolithic AL2024-T3 and the TFMLs are very similar at the same cycles to failure.|JTE100670|Journal Article|182006353||JTE100670||6|1|0|2007-05-01 0:00:00|10.1520/JTE100670|2006-11-15 0:00:00||||||2006-05-30 0:00:00|2006-09-28 0:00:00|0090-3973||100670|963 35|3|2007|1-7|JTE0705|Zofka A, Marasteanu M|Development of Double Edge Notched Tension (DENT) Test for Asphalt Binders|asphalt binder, fracture test, fracture toughness|
This paper presents the experimental details of performing double edge notched tension (DENT) fracture tests on asphalt binders. The testing is performed using an existing direct tension (DT) test device and modificed molds for preparing the test specimens. The fracture toughness values obtained from DENT tests perfomed on nine different asphalt binders are in the reasonable agreement with the values published by other researchers. Further evaluation of the DENT and DT test results indicate that both produce similar trends in terms of failure strains. The
In this study, a subtractive clustering fuzzy identification method and a Sugeno-type fuzzy inference system are used to monitor the hole quality in a drilling. The model for the hole quality is identified by using the hardness of the workpiece, the cutting speed, and the cutting feed as input data and the hole quality features of hole roughness, roundness error, and oversize error as the output data. The process of model building is carried out by using subtractive clustering in both the input and output spaces. A minimum error model is obtained through exhaustive search of the clustering parameters. The fuzzy model obtained is capable of predicting the hole quality for a given set of inputs (hardness of the workpiece, the cutting speed, and the cutting feed). Therefore, one can predict the quality of the drilled hole for a given set of working parameters. The fuzzy model is verified experimentally using different sets of inputs. This study deals with the experimental results obtained during drilling on medium carbon steel (AISI 1060), aluminum, and brass.|JTE12575|Journal Article|182007353||JTE12575||6|1|0|2007-05-01 0:00:00|10.1520/JTE12575|2006-11-15 0:00:00||||||2004-02-05 0:00:00|2006-10-17 0:00:00|0090-3973||12575|965 35|3|2007|1-9|JTE0705|Hajj EY, Siddharthan RV, Sebaaly PE, Weitzel D|Laboratory-based Unified Permanent Deformation Model for Hot-Mix Asphalt Mixtures|permanent shear strain, Drucker-Prager failure envelope, factor of safety, unified model, triaxial strength test, repeated load triaxial, repeated shear constant height|
Conventionally, the resistance of hot-mixed asphalt (HMA) mixtures to permanent deformation is measured by repeated load triaxial (RLT) or repeated shear at constant height (RSCH) testing. The data from these tests have been treated as independent datasets in the prediction of rutting potential in HMA layers. This paper presents a unified permanent deformation model using response measurements made from both tests. The new model quantifies the accumulated permanent shear strain as a function of number of load cycles and factor of safety (FOS). The factor of safety is defined in the
Stress corrosion cracking (SCC) is one of the greatest concerns in nuclear aging and degradation, and studies on the measurement of stress corrosion crack growth rates (CGR) and the effects of environmental, material, and mechanical parameters on the CGR have been performed using mainly fracture mechanics specimens. However, the stress states for the fracture mechanics specimens are different from that of real field components and there is concern about the applicability of the data obtained from fracture mechanics specimens to the evaluation of SCC behaviors in real field components. In this study, in order to obtain SCC for specimens that have a similar shape of real field components under complicated stress states, an SCC test methodology using specimens in the shape of tubes was developed. Its effectiveness was verified by performing an SCC test using a mock-up of a bottom mount instrumentation tube of a pressurized water reactor (PWR) under a simulated PWR primary water environment. Intergranular SCC was created in the mock-up specimen using the developed SCC test methodology and SCC crack growth rate for the mock-up specimen was measured.|JTE100628|Journal Article|182006353||JTE100628||5|1|0|2007-05-01 0:00:00|10.1520/JTE100628|2006-11-22 0:00:00||||||2006-05-01 0:00:00|2006-10-24 0:00:00|0090-3973||100628|967 35|3|2007|1-6|JTE0705|Hefer AW, Little DN, Herbert BE|Bitumen Surface Energy Characterization by Inverse Gas Chromatography|bitumen, adhesion, bitumen-aggregate adhesion, surface energy, surface tension, inverse gas chromatography|
Modern surface energy theory has been identified in recent years as an attractive tool by which to select compatible bitumen-aggregate combinations. In addition, this approach offers the potential to quantitatively assess moisture susceptibility of these material combinations. The success of implementing this technology depends on the availability of techniques that allow efficient and reliable surface energy characterization of the materials under consideration. This paper focuses on bitumen surface energy characterization employing inverse gas chromatography (IGC). The authors report detail column preparation and test methodologies, and provide a precision statement for this technique. Analysis procedures and results presented demonstrate successful application of this technique with modern thermodynamic theory to acquire bitumen surface energy components. The technique allows testing at different temperatures and results are in agreement with conceptual and theoretical expectations. Surface energies derived from IGC compare reasonably well with mechanical surface tension values from the literature. Results suggest that surface energies do not vary considerably between different bitumen types, indicative of the controlling role of aggregate type in bitumen-aggregate adhesion.|JTE100080|Journal Article|182007353||JTE100080||6|1|0|2007-05-01 0:00:00|10.1520/JTE100080|2006-12-06 0:00:00||||||2005-05-19 0:00:00|2006-08-28 0:00:00|0090-3973||100080|968 35|4|2007|1-9|JTE0707|Brieu M, Diani J, Bhatnagar N|A New Biaxial Tension Test Fixture for Uniaxial Testing Machine—A Validation for Hyperelastic Behavior of Rubber-like Materials|biaxial tensile, uniaxial test, hyperelastic, rubber-like materials, large deformation|
A new mechanism for a biaxial tension test is developed for loading an in-plane specimen simultaneously in two principal directions. This mechanism can be adapted to any uniaxial tension test machine and thereby it reduces the cost of conducting tests on expensive machines. It provides a uniform state of equibiaxial tension necessary for procedure characterizing the biaxial loading of any material system and particularly for understanding the hyperelastic behavior law of rubber-like materials for large deformations. The mechanism can also be utilized for evaluating an interaction coefficient of anisotropic or orthotropic materials like reinforced composites that can help in characterizing and predicting failure behavior. As a sample case, the experimental results obtained by this new mechanism are validated with the existing models for two rubber-like materials undergoing hyperelasticity.|JTE100688|Journal Article|182007354||JTE100688||9|1|0|2007-07-01 0:00:00|10.1520/JTE100688|2006-12-06 0:00:00||||||2006-06-08 0:00:00|2006-10-25 0:00:00|0090-3973||100688|969 35|4|2007|1-8|JTE0707|Kawamoto K, Yoshimitsu S, Noguchi H, Yoshimura T|Laser Welding Conditions to Improve Tensile Strength and Fatigue Strength of a Lap Joint in Aluminum Alloys|laser welding, aluminum alloy, lap joint, tensile strength, fatigue strength, heat input, gap width, reliability|
This research shows a procedure for seeking a domain of conditions under which the tensile strength and fatigue strength are improved in lap joints of aluminum alloys made by laser welding. Laser welding parameters involve the following three factors: gap width, welding speed, and laser power. The following conditions were obtained in this research. (a) When searching for favorable welding conditions, the required work involves only observing the states around the weld-zone. (b) In order to improved the fatigue strength, it is necessary to prevent the generation of lack of fusion by the shortage of heat input and a crack near the toe of the weld due to the excess heat input. Using the results, the above-mentioned simple method is shown.|JTE100077|Journal Article|182007354||JTE100077||8|1|0|2007-07-01 0:00:00|10.1520/JTE100077|2007-01-10 0:00:00||||||2003-12-23 0:00:00|2006-12-05 0:00:00|0090-3973||100077|970 35|4|2007|1-6|JTE0707|Bell JM, Odom EM|An Experimentally-Based Analytical Model of the Stress Field in an Iosipescu Composite Test Specimen|graphite/epoxy composites, Iosipescu shear testing, stress distributions, strain gage|
Typically, the reduction of the load and strain data obtained during an Iosipescu shear test assumes constant shear strain and shear stress distributions. While this is nominally correct and simplifies the data reduction, it provides no insight into the shear stress-shear strain distribution and can lead to theoretically inconsistent experimental results. In this study, an Idaho Iosipescu test fixture, two sizes of strain gages, an assumed power law for the strain distribution, and the Richard-Blacklock stress-strain relationship have been combined to model both the shear strain and the shear stress profile across the gage section. The results show a strain distribution dependent on both load and laminate layup and the difference between the shear stress and the shear strain profile. The initial shear moduli found from the nonlinear model show an insignificant difference between the two layups which is in agreement with composite theory.|JTE100543|Journal Article|182007354||JTE100543||6|1|0|2007-07-01 0:00:00|10.1520/JTE100543|2007-01-03 0:00:00||||||2006-03-15 0:00:00|2006-12-08 0:00:00|0090-3973||100543|971 35|3|2007|1-11|JTE0705|Kapoor K, Padmaprabu C, Ramana Rao SV, Sanyal T, Kashyap BP|Texture Evaluation in Zr-2.5 % Nb Pressure Tubes Using Kearn's
The anisotropic properties of Zr-2.5 wt % Nb pressure tube material, used in pressurized heavy water reactors (PHWR) depend primarily on the texture associated with the material. Particularly properties such as coefficient of thermal expansion, mechanical anisotropy, irradiation growth, stress corrosion cracking, and delayed hydrogen cracking, are directly correlated. Thus, the knowledge of preferred orientation becomes an essential prerequisite for property evaluation. In the present paper the correlation between the preferred orientation factor, namely Kearn's
This paper presents results from a design study for a new journal bearing test rig intended to set new standards of accuracy. The paper summarizes a review of previous rigs and experimental techniques, with consideration and selection of the general design features most likely to give high accuracy in a new rig. Certain sources of error are identified and described, including those associated with the measurement system and build errors. A numerical assessment of the sensitivity to errors in selected experimental configurations is presented. In addition, methods of controlling uncertainties are discussed. This paper would be of interest to practicing engineers and researchers, either already involved, or new, to experimental journal bearing testing.|JTE100116|Journal Article|182007354||JTE100116||8|1|0|2007-07-01 0:00:00|10.1520/JTE100116|2007-02-21 0:00:00||||||2005-05-17 0:00:00|2007-01-18 0:00:00|0090-3973||100116|973 35|4|2007|1-8|JTE0707|Wasiuddin NM, Fogle CM, Zaman MM, O'Rear EA|Characterization of Thermal Degradation of Liquid Amine Anti-Strip Additives in Asphalt Binders Due to RTFO and PAV-Aging|asphalt binder, anti-strip additives, thermal degradation, RTFO-aging, PAV-aging, surface free energy, dynamic Wilhelmy plate method, contact angle, acid, base|
In this study, thermal degradation of amine-based liquid anti-strip additives was evaluated due to RTFO-aging and PAV-aging according to AASHTO T 240 and AASHTO R 28 test methods, respectively. The surface free energy (SFE) characteristics of asphalt binders before and after aging were used as a tool for this evaluation. Two asphalt binders, namely PG 64-22 and PG 70-28, and two anti-strip additives, namely AD-Here HP Plus and Redicote E-6, were evaluated. It was observed for 0.75 % AD-Here HP Plus in PG 64-22, mixing at 163°C is more effective than mixing at 145°C with respect to increase in SFE. Also, both RTFO and PAV-aging decrease the total SFE of asphalt binders; both the aging processes are more effective in PG 64-22. In addition, the beneficial effect of anti-strip additives in acid-base characteristics of asphalt binders is severely reduced by RTFO and PAV-aging. Finally, the chemical model of asphalt binder, proposed by Wasiuddin et al., was expanded to include the SFE characteristics of asphalt binders due to aging.|JTE100660|Journal Article|182007354||JTE100660||8|1|0|2007-07-01 0:00:00|10.1520/JTE100660|2007-02-21 0:00:00||||||2006-05-24 0:00:00|2006-12-12 0:00:00|0090-3973||100660|974 35|4|2007|1-6|JTE0707|Lacroix F, Tougui A, Berton G, Ranganathan N, Neelakantan NR|Tensile Creep Studies on Filled Polychloroprene Elastomer|creep, polychloroprene, elastomer, four-parameter equation, Findley equation|
Tensile creep data on an elastomeric material, polychloroprene, are presented in this paper. The data were collected at four temperatures, 20, 40, 80, and 110°C and four stress levels, 0.4, 0.6, 0.8, and 1 MPa. Each experiment was conducted over a time period of about twelve hours. Two different mechanisms seem to operate for the creep behavior in these ranges. At the lower temperatures, 20 and 40°C, the data are fitted with a new four-parameter equation; the data at different stress levels are combined into a single curve, which can be called a master plot. At the higher temperatures, 80 and 110°C, for the time period used, a single equation cannot fit the data and two equations are used, a four-parameter equation for the initial time, and the Findley equation for the later time.|JTE100081|Journal Article|182007354||JTE100081||6|1|0|2007-07-01 0:00:00|10.1520/JTE100081|2007-03-14 0:00:00||||||2004-09-07 0:00:00|2007-01-17 0:00:00|0090-3973||100081|975 35|4|2007|1-9|JTE0707|Al-Qadi IL, Fini EH, Elseifi MA, Masson J, McGhee KM|Development of a Viscosity Specification for Hot-Poured Bituminous Sealants|viscosity, crack sealant, shear rate, non-Newtonian fluid|
Current crack sealant specifications focus on using simple empirical tests such as penetration, resilience, flow, and bonding to cement concrete briquettes (ASTM D 6690) [1] to measure the ability of the material to resist cohesive and adhesive failures. There is, however, no indication of the pertinence of these standard tests to predict the success of field installation and sealant performance. In an effort to bridge the gap between sealant fundamental properties and field performance, performance-based guidelines for the selection of hot-poured crack sealants are currently being developed. This paper proposes a new viscosity test procedure to help assess the propensity of sealants to wet the crack surface during installation. The proposed procedure calls for the use of a Brookfield rotational viscometer equipped with a modified spindle rod and an SC4-27 spindle at a speed of 60 r/min. Sealants are heated 20 min at the recommended installation temperature and the viscosity is measured after 30 s of spindle rotation in the hot sealant. These experimental conditions provide viscosities representative of sealant viscosity at shear rates during field application. The repeatability for within laboratory and between laboratories was found to be 5.4 and 17 %, respectively. This repeatability is comparable with the corresponding variability of the SuperPave viscosity test for asphalt binders.|JTE100260|Journal Article|182007354||JTE100260||9|1|0|2007-07-01 0:00:00|10.1520/JTE100260|2007-03-14 0:00:00||||||2006-01-14 0:00:00|2007-01-17 0:00:00|0090-3973||100260|976 22|1|1994|3-13|JTE9401|McKeighan PC, Hillberry BM|On the Uncertainties Involved in Quantifying the Fracture Toughness of Al-Li-X Alloys|Al-Li-X alloys, crack deflection, delamination, fracture behavior, fracture toughness, mixed-mode fracture, nonlinear fracture|The fracture behavior of an extruded Al-2.6Li-0.09Zr alloy in a near peak-aged and over-aged condition was found to be primarily intergranular with formation of non-Mode I, crack-divider delaminations at the crack tip especially in the over-aged temper. This complex, irregular fracture mode results in behavior that cannot be accurately measured using the conventional J- and K-based toughness parameters and testing methods. Other observed fracture characteristics that force reassessment of the traditional testing methodologies include crack length variations, mixed mode fracture from crack deflection, and apparent plasticity. The observed crack length variations through the specimen thickness led to 4 to 8% uncertainty in the K-curve for the specimens used. Furthermore, crack deflection corrections lead to an average 4 to 7% and maximum 15 to 18% apparent toughness increase for the material. The alloy exhibited nonlinear load-displacement behavior during fracture that could be corrected by using a plastic zone size modification. The analyses outlined provide insight into the roles the various mechanisms play in the fracture process of this alloy. However, the conventional toughness measures were inadequate in treating the observed fracture behavior.||Journal Article|661|12542|||11|0|1|1994-01-01 0:00:00|10.1520/JTE99903485|||||||||0090-3973||99903485|1 22|1|1994|14-19|JTE9401|Sharpe Jr. WN, Böhme W|Dynamic Fracture Toughness Measurements on Small Charpy SpecimensA Preliminary Study|Charpy tests, crack tip opening displacement (CTOD), dynamic fracture toughness, fracture mechanics, interferometry, small specimens|A technique for measuring dynamic fracture toughness on small specimens is described and preliminary data are presented. Dynamic crack tip opening displacements (CTODs) are measured with laser interferometry over times as short as 10 ms. The measured displacement is converted to stress intensity values via the equations of linear elastic fracture mechanics and the peak value obtained is taken as the dynamic fracture toughness. Two materials were tested at two different loading rates; a brittle plastic at 103 and 104 MPa-m½/s and a ceramic 5 × 104 and 106 MPa-m½/s. The results from this new technique were compared with simultaneous results from an instrumented Charpy hammer and, in some cases, from foil gages on the specimens. At the slower rates, the agreement among the results is acceptable. At the higher rates, the instrumented hammer technique is no longer valid. The technique is potentially useful on small, brittle specimens at room and high temperatures.||Journal Article|661|12543|||6|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903486|2 22|1|1994|20-29|JTE9401|Bhattacharya S, Kumar AN|R-Curve Generation and CTOD Evaluation Considering Maximum Crack Growth Size and Parabolic Crack Front|R-curve, area measurement, average crack growth size, crack-tip opening displacement (CTOD), maximum crack growth size, seven point measurement|The standard methods of estimating the average size of the slow crack growth region as described in BS 5762 (Crack Opening Displacement (COD) and ASTM E 1290 (Test Method for Crack-Tip Opening Displacement (CTOD) Fracture Toughness Measurement) are cumbersome, painstaking, time consuming, and dependent on several factors; e.g., section thickness, the nature of crack front profile, and the number of measurements. Often errors are introduced in determining the average crack size which in turn affect the determination of critical CTOD value. However, several merits are associated with the use of maximum crack size. A theoretical relationship is established between the two physical quantities by assuming a parabolic nature of the slow crack growth front profile, which is supported by experimental data points. In situations of large crack growth, the crack profile tends to change from a parabolic to a semicircular crack front. A new approach is proposed to make use of the maximum crack size to generate R curves that can be extended to yield critical CTOD values. The nonlinear regression analysis of the CTOD-maximum crack size R curve yields critical CTOD values in agreement with the values that may be obtained by BS 5762. However, the linearly regressed and extrapolated critical CTOD values are found to be highly conservative. Alternatively, the average crack size may be obtained theoretically by using maximum crack size data to determine CTOD values following BS 5762.||Journal Article|661|12544|||10|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903487|3 22|1|1994|30-35|JTE9401|Faucher B|Crack Length and J-Integral Expressions for Specimens Loaded in Tension|J-integral, compliance, tension specimens|Equations are developed to calculate the J-integral from the area under the load-displacement curve obtained with center-cracked M(T) and double-edge-notched DE(T) tension specimens. Analytical expressions are also derived to calculate the crack length from unloading compliance.||Journal Article|661|12545|||6|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903488|4 22|1|1994|36-41|JTE9401|Schmitt FC, Matthews JM|Controlling Data Acquisition, and Data Processing for Axial and Shear Creep Tests Using a Computer|computer control, creep test, data acquisition, data processing, repeated load test|The objective of this paper is to provide an inexpensive way of conducting uniaxial creep and shear creep tests, data acquisition, and data processing using a computer. A microcomputer, a math coprocessor, and a graphics laser jet printer were used. A multi-function analog-digital-input-output expansion board increased the computer capacity enabling better precision, data acquisition, and signal analysis. A load cell was used to measure the loads while two linear variable differential transducers (LVDT) were used to monitor the deformations. A signal conditioning unit was used to excite the load cell and LVDTs and to transform the voltage output of the two digital analog channels into electric currents. Software developed at the University of California, Berkeley was used to conduct the tests. Hard copies of the computer output were obtained showing the relationship between the creep compliance and the time of loading. An example of the application of the creep test results for predicting the permanent deformation of the asphaltic layer of a heavy duty highway is included.||Journal Article|661|12546|||6|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903489|5 22|1|1994|42-44|JTE9401|Sivaganthan J, Ganesan AR, Tan BC, Low KS, Sirohi RS|Study of Steel Weldments Using Electronic Speckle Pattern Interferometry|Electronic Speckle Pattern Interferometry (ESPI), steel weldments|This paper describes the use of Electronic Speckle Pattern Interferometry (ESPI) in the detection of defects in welded steel plates. Experimental results obtained using this technique are described.||Journal Article|661|12547|||3|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903490|6 22|1|1994|45-47|JTE9401|Changizi K|A Computer Method of Analysis for Tire Wear Characterization, Identification and Classification|Fourier analysis, tire rib profile, tire rubber loss, tire runout measurements, tire wear classification|A tire's rib profile before and after use can be determined by using two sets of measurements. These measurements are the tire runout values taken along the ribs before and after use. Superimposing these values over a circle with a predetermined constant radius that depends on the overall unloaded diameter of the tire as well as the maximum peak-to-peak runout value of the rib will result in the tire's rib profile. The difference of areas bounded between the rib's profile and the specified circle, before and after use, is a quantitative measure of tire wear along the rib. Therefore, it is the primary objective of this paper to outline a computer method of analysis, not only to generate the tire's rib profile before and after use, but also to provide a quantitative measure of rubber loss around the circumference of each tire rib. The significance of generating the profile is the ability to observe and locate the highest and lowest points of the tire along the rib and to inspect a tire for defects. This can be especially important for the tire manufacturers at their line of production. Among other important characteristics of this proposed method is the potential for predicting the wear nature of a tire rib, after use, by quantifying the loss of the rubber along the rib and by the process of decomposing each rib's profile into the sum of sinusoids with appropriate amplitudes and phase angles. This process of decomposition, which is commonly known as Fourier Analysis, can identify the harmonics with highest contributions to the shape of the profile. Harmonics with highest contributions play an important role in shaping the profile. Two tires with similar or close harmonic contents in their rib's profile, after use, can be classified as tires with identical wear pattern.||Journal Article|661|12548|||3|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903491|7 22|1|1994|48-51|JTE9401|Green HJ|Physiologic Challenges Induced by Participation In Ice HockeyImplications for Training|conditioning, electrolytes, energy, environment, fluid, ice hockey, neuromuscular, status of participant|Training programs for ice hockey players have two fundamental objectives; namely, to optimize performance and to minimize the risk of injury. The design of efficient and successful programs to meet these purposes depends on a careful analysis of the physiological demands of the game and the environment in which it is played. Moreover, if the program is to meet individual needs, the physical and physiological status of the player must be considered. Ice hockey is a demanding sport that involves the recruitment of essentially all of the skeletal muscles of the body in order to perform the diverse skills of the game. These skills are performed over various ranges of movement, at various velocities and loads, and usually involve several large muscles acting synergistically. Moreover the extended nature of the game, performed over three periods, results in numerous repetitions of each task. Collectively, the repeated performance of these tasks impose extreme demands on respiratory, cardiovascular, neural, muscular, metabolic, and thermoregulatory systems of the body. The physiological demands may be further exaggerated given the protective equipment that is worn and the fact that abnormally high temperatures and humidities may be present. Proper preparation can only be realized by exposing the participant to progressive routines designed to systematically challenge each of the physiologic systems in a manner appropriate to game conditions.||Journal Article|661|12549|||4|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903492|8 22|1|1994|52|JTE9401|Perlov A|Introduction to Workshop on Accuracyt of Load and Strain Measurement of Testing Machines||||Journal Article|661|12550|||1|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903493|9 22|1|1994|53-56|JTE9401|Albright FJ, Annala J|Practical Aspects of Dynamic Verification of Extensometers: Part IThe Concepts|dynamic calibration, extensometers, frequency response, strain measurement, verification|Material property studies frequently require the measurement of load and strain. Accurate measurement of both parameters is essential. Methods for accurate static calibration and verification of load transducers and extensometers are well established. More recently, standard practices have been developed for the dynamic calibration of load transducers. Still in its infancy is a standard method for dynamic verification of extensometers. Dynamic verification introduces a wide range of new issues. These encompass not only the transducer but also the conditioning electronics and actual test machine. Static calibration permits the "elimination" of nearly all dynamics, whereas dynamic verification must be done in the presence of these dynamic effects. This paper outlines the various concepts that need to be understood when performing the dynamic verification of an extensometer. Problems related to computer aided verification are emphasized, issues of aliasing and resolution in particular.||Journal Article|661|12551|||4|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903494|10 22|1|1994|57-62|JTE9401|Albright FJ, Annala J|Practical Aspects of Dynamic Verification of Extensometers: Part IIActual Examples|computer assisted data acquisition, dynamic calibration, extensometers, frequency response, verification|Verification and calibration of an extensometer requires operation at multiple points within the desired operating range. Whereas static calibrations observe changes in sensitivity at different levels within the transducer operating range, dynamic calibrations require duplicating that range of test levels for a range of operating frequencies. Additionally, although the static accuracy of an extensometer is relatively independent of the test machine, dynamic accuracy was believed to be quite dependent. Test results for dynamic verification of several extensometers are presented. The focus of the tests was to gain an understanding of the advantages and disadvantages of different methods of verification. Testing was generally in accordance with ASTM E 467, Practice for Verification of Constant Amplitude Dynamic Loads in An Axial Load Fatigue Testing Machine. Two excitation methods were used: discrete frequency and pseudo-random. Evaluation of a proposed revision to ASTM E 467 is included. Use of a computer to provide an efficient, high-accuracy method of verifying the calibration of an extensometer was explored. Further testing is recommended to determine if extensometer dynamic verification must be done on the actual test setup, and to what extent it is repeatable.||Journal Article|661|12552|||6|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903495|11 22|1|1994|63-69|JTE9401|Roebuck B, Lord JD, Cooper PM, McCartney LN|Data Acquisition and Analysis of Tensile Properties for Metal Matrix Composites|metal matrix composites (MMCs), tangent and secant modulus measurements, tension test method, Young's modulus measurement|Problems arise when existing standard tension tests are used for the measurement of the properties of metal matrix composites (MMCs), largely because the elastic limits in these materials are low due to intrinsic residual stresses. A new and validated data acquisition and analysis system has been developed to provide reference data for comparison with the results of two U.K. interlaboratory exercises on the tension test method for MMCs. Particular attention is paid to assessing an automatic system for calculating Young's modulus from the input data and using plots of secant or tangent modulus against stress or strain to present information on properties in a clear and succinct manner, and to methods for validating the software. The results of both interlaboratory exercises, on different types of MMCs, showed that the analysis system produced the smallest deviation from the mean.||Journal Article|661|12553|||7|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903496|12 22|1|1994|70-80|JTE9401|Tovey FM|Measurement Uncertainty Analysis of a Transfer Standard Force Calibration System|force transducer calibration, force transducers, measurement error, measurement uncertainty|Force transducer calibration may be performed by means of dead weights or by comparison with a transfer standard. Directly applied dead weights with traceability to the National Institute of Standards and Technology (NIST) are primary force standards. Low-capacity force transducers are generally calibrated by primary standards, but for force transducer calibrations above 1000 lb (453.6 kg), many force transducers are calibrated by means of secondary force standards used as transfer standards. The purpose of this paper is to provide a measurement uncertainty analysis of transfer standard force calibration at one test facility. Significant error sources are identified and quantified. The methodology presented is generally applicable; however, the error evaluations are specific to the measurement process and test equipment used.||Journal Article|661|12554|||11|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903497|13 22|1|1994|81-83|JTE9401|Zhu YG, Wu XR, Yang YA|A New Restraint for High-Load-Transfer Fastener Fatigue Test|fastener, fatigue, fatigue test, joints, rivet|A test somewhat different from the MIL-STD-1312 test 21 (Shear Joint Fatigue-Constant Amplitude) was explored by using a new type of restraint. Rivet fasteners of two kinds of materials were tested under constant amplitude fatigue loading. The new restraint facilitated the test program and reduced the bending load more efficiently than the current method. Fatigue behavior of aluminum alloy and high-strength steel with single-lap rivet fastener specimens was investigated under different load levels.||Journal Article|661|12555|||3|0|1|1994-01-01 0:00:00||||||||||0090-3973||99903498|14 22|2|1994|91-97|JTE9403|Makabe C, Kaneshiro H, Yara H|Fatigue Crack Propagation in a Specimen with a Complicated Cross-Section; Characterization of the Stress Intensity Factor|crack closure, crack propagation, cross-section of specimen, fatigue, groove, stress intensity factor|In order to predict the fatigue life of machine equipment, the fatigue crack propagation law has up to now been investigated using specimens with a simple cross-section shape. In this study, a specimen with three grooves cut in the loading direction was used to clarify crack propagation and crack closure behavior at points of discontinuous change in thickness. It was found that the crack propagation curve showed a complicated variation in the vicinity of the grooves and that the variation of crack closure behavior correlated well with it. The stress intensity factor was evaluated using the calibration curve between the crack propagation rate and the effective stress intensity factor range obtained from a similar smooth specimen. Results showed that the stress intensity factor of the grooved specimen was higher in front of the first groove and lower behind it, compared to the smooth specimen. As the crack crossed the first groove, the crack propagation rate exhibited a local maximum as a function of the maximum value of stress intensity factor.||Journal Article|662|12556|||7|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903499|15 22|2|1994|104-110|JTE9403|Odom EM, Adams DF|Development of an Improved Compression Specimen Geometry for Unreinforced Polymers|anelastic, buckling, compression, nonlinear, slenderness ratio, thermosetting polymer, unreinforced|One of the recommended compression specimen geometries for plastics in ASTM D 695, Test Method for Compressive Properties of Rigid Plastics, is a straight-sided cylinder or prism. This end-loaded specimen tends to barrel at high strains. Additionally, if modulus is desired, the standard suggests that the specimen have extra length to avoid end constraints. Therefore, compression specimens for modulus can fail at a different stress level than compression specimens for strength. To overcome these problems, a compression specimen with a gage section of reduced area which is end-loaded but side supported was developed. Additional experimental observations of the thermosetting polymer of interest included a nonlinear compressive stress-compressive strain response which required a parabolic constitutive relationship to model, an observation of a significant anelastic material response, and a material response termed anelastic buckling. These observations of material behavior had not previously been observed.||Journal Article|662|12557|||7|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903500|16 22|2|1994|111-116|JTE9403|Johnson NL, Earthman JC|Numerical Model of Primary Creep Deformation in a Novel Double Shear Specimen|creep deformation, creep rupture, finite element modeling, multiaxial stress states, primary creep, shear stress state|Three-dimensional finite element calculations were performed for primary creep deformation in a novel double shear specimen. Two characteristic creep behaviors were considered: one in which the stress exponent, n, is equal to 3 and another in which n is equal to 5. Both models resulted in a quasi-stationary stress state in which the principal stresses change only slightly with time while the von Mises effective stress and principal facet stress reach essentially constant values. The uniformity of this quasi-stationary stress state throughout the gage section indicates that it may be used to characterize the overall stresses driving creep deformation and damage.||Journal Article|662|12558|||6|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903501|17 22|2|1994|117-120|JTE9403|Gilbert CJ, McNaney JM, Dauskardt RH, Ritchie RO|Back-Face Strain Compliance and Electrical-Potential Crack Length Calibrations for the Disk-Shaped Compact-Tension DC(T) Specimen|back-face strain compliance, disk-shaped compact-tension DC(T) specimen, electrical-potential calibration|Back-face strain compliance and electrical-potential crack length calibrations have been experimentally determined for the disk-shaped compact-tension DC(T) specimen. Finite-element modeling was used to ascertain the back-face strain distribution at several crack lengths to determine the significance of inconsistent gage placement. The numerical solutions demonstrated good agreement with experiment, especially at smaller crack lengths when the back-face strain gradients are minimal. It is concluded that precise gage placement is only critical when the crack tip closely approaches the back of the test specimen.||Journal Article|662|12559|||4|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903502|18 22|2|1994|121-126|JTE9403|Miyahara K, Matsuoka S, Nagashima N, Masuda H|Application of Surface Fabrication to Strain Measurement in Nanometer Scale with the Scanning Tunneling Microscope|nanofabrication, scanning tunneling microscope (STM), strain measurement|In this paper we describe the application of surface fabrication to the strain measurement in a nanometer scale with a scanning tunneling microscope (STM). In the electrical surface fabrication with the STM, hemispherical mounds whose radius and height were about 10 nm were created by applying a voltage pulse higher than 2.45 V between a gold STM tip and gold specimen. In the mechanical surface fabrication, indentations whose minimum depth was about 10 nm, were created by the contact of a conductive diamond tip with the gold specimen. The lattice of mounds or indentations was arranged in ten columns of ten rows at 45 nm pitch in the region of 450 × 450 nm. Comparing the two STM images before and after making a 50-nm-deep indentation on the lattice of small indentations, the displacement distribution was measured in the nanometer scale at each small indentation. Finally, strain distribution was calculated from the displacement distribution by using triangular elements.||Journal Article|662|12560|||6|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903503|19 22|2|1994|127-131|JTE9403|Sample VM, Field DP|Constant Temperature-Compensated Strain Rate Testing of Aluminum|aluminum, constitutive response, deformation induced heating, mechanical testing, temperature-compensated strain rate|Temperature and strain rate have long been identified as the external variables dictating material response during deformation. The Zener-Hollomon parameter, Z, is a temperature-compensated strain rate defining the interrelationship between the two variables. Investigation of the constitutive response of a material requires well-defined testing conditions in order to properly identify material behavior. Mechanical testing at constant Z values offers the advantage of using well-defined deformation conditions when isothermal control cannot be maintained during deformation. To perform such tests real time feedback control of the strain rate is required. In addition, at high strain rates where deformation heating becomes significant, thermocouple response is not rapid enough to provide feedback signal adequate for control of the test. Under these circumstances it is necessary to predict deformation heating of the specimen as a function of the test parameters and control the strain rate based upon the estimated specimen temperature. Results of constant Z tests are presented showing the capabilities of the control system. Deformation heating is accounted for by a simple equation assuming a near adiabatic process which predicts the dissipation of heat through the surrounding environment. An application of the constant Z test procedure for modeling material behavior is briefly discussed. The ability to perform deformation experiments at constant Z values offers significant advantages in gaining an understanding of the constitutive response of materials.||Journal Article|662|12561|||5|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903504|20 22|2|1994|132-138|JTE9403|Moore ID|Local Strain in Corrugated Pipe: Experimental Measurements to Test a Numerical Model|finite element analysis, high-density polyethylene (HDPE), parallel plate test, stiffness, strain, three-dimensional (3-D) response|Measurements of local strain in corrugated steel and high-density polyethylene (HDPE) pipe are used to test the effectiveness of a three-dimensional finite element analysis. Measurements were made at the horizontal diameter for the pipes subjected to parallel plate loading, a load condition that produces significant strain gradients around the pipe as well as through the corrugation. The test values are used to evaluate the performance of elastic analysis for both steel and polyethylene pipes, as well as viscoelastic analysis used for the polyethylene pipe alone. It is demonstrated that the theoretical model generally yields estimates of local strain within 5 to 15% of the measured values. The viscoelastic predictions of local strain through a load-unload cycle on the HDPE pipe were very good. The load-deflection response of HDPE is predicted well for monotonic loading, but improvements in the viscoelastic model for HDPE appear necessary to improve predictions through a full load unload cycle.||Journal Article|662|12562|||7|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903505|21 22|2|1994|149-160|JTE9403|Ozkan E|Thermal and Mechanical Properties of Cellular Polystyrene Polyurethane Insulation Materials Aged on a Flat Roof in Hot-Dry Climate|aging, cellular plastics, compression test, dimensional stability/compressive creep test, expanded polystyrene, extruded polystyrene, flat roof, foamed polyurethane, natural weathering, surface temperature, thermal conductivity (k), thermal insulation|Cellular polymers, which have been increasingly used for thermal insulation of external walls and roofs since the 1970s, degrade in some cases. The heat transmission of a cellular polymer insulator, the k value, is predominantly dependent on the heat conduction of the air or gas remaining in the cells. An insulator may be aged and start transmitting more energy due to replacement of cell content with different gases or moisture or both, changes in size, softening and creeping under pressure and heat, or penetration of water or mineral particles into cells, or a combination thereof. The solid face also degrades due to ultraviolet light, heat and atmospheric oxygen. A research project2 was carried out from January 1988 to December 1991 to investigate the performance of flat roofs, waterproofing, and thermal insulation materials in the hot-dry climatic region of Saudi Arabia. In this context a field station was built and operated for weathering of roofing and insulation materials and for monitoring the surface and the inner temperatures of the applied roof systems. Basically, two types of cellular polymers, expanded polystyrene and foamed polyurethane, were installed on the roof of the station for insulation. Specimens taken from the fresh, stored, and weathered polystyrene and polyurethane foams were tested to evaluate them according to the selected properties of thermal conductivity, compressive strength at relative deformation, and dimensional stability at elevated temperature. The test results were compared with the requirements presented in the literature and the standard specifications.||Journal Article|662|12563|||12|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903506|22 22|2|1994|161-167|JTE9403|Fishman KL, Machmer D|Testing Techniques for Measurement of Bulk Modulus|bulk modulus, deformation jacket (DJC) method, elastomeric bearings, elastomers, piston method, volume change device (VCD) method|The objective of this study was to examine prospective tests for determining the bulk modulus of elastomers used in the construction of elastomeric bearings. Because elastomeric materials are nearly incompressible, relatively slight volume changes are experienced during isotropic compression, sizably governing the accuracy of test measurements. For this reason major topics of interest are equipment calibration, test repeatability, and error accountability. Test methods explored included use of a deformation jacket, a fluid displacement volume change measurement device, and load ram displacement for measurement of volume change. For verification of test methods specimens of Adeprene were tested. Results from all test methods were found to be suitably, but not equally, repeatable. Considering ease of operation, and acceptability of errors, the load ram method is found to be superior compared to other methods investigated.||Journal Article|662|12564|||7|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903507|23 22|2|1994|168-174|JTE9403|Sorini SS|Development and Validation of a Standard Test Method for Sequential Batch Extraction of Waste with Acidic Extraction Fluid|acidic precipitation, extract, extraction, extraction fluid, leachate, sequential batch extraction, teaching, waste leaching technique|A project was conducted to develop and validate a sequential batch extraction method using a dilute acid solution as the extraction fluid. The method was developed by ASTM Task Group D-34.02.01 on Waste Leaching Techniques, and calls for the pH of the extraction fluid to reflect the pH of acidic precipitation in the geographic region where the material being tested is to be disposed. A collaborative study of the method was conducted to determine the multiple-laboratory and single-operator precision of the extraction procedure when applied to two different waste materials using two different pH values. A general statement on the precision of the method that covers all wastes, analytical parameters, and extraction fluid pH values cannot be made because the data generated in the collaborative study are specific to the test materials, extraction fluid pH values, and elements of interest in this study. However, the data generated in the study provide information on the variability that can be expected between test results when the method is used by one or more laboratories. This information will help potential users assess the usefulness of the method in their proposed applications.||Journal Article|662|12565|||7|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903508|24 22|2|1994|175-178|JTE9403|Anabtawi MZ, Nazzal JM|Effect of Composition of EI-Iajjun Oil Shale on Its Calorific Value|calorific values, oil shale, physical properties|A geochemical analysis of El-lajjun oil shale in Jordan was carried out. It was found that El-lajjun oil shale consists of the following groups: organic matter, biogenic calcite and apatite, detrital clay minerals, and quartz. The calorific values of 100 samples of shale were determined. The effect of bore depth, calcium carbonate, organic carbon, and sulfur content on the calorific values were studied. Results were well correlated by the following equation Calorific value = 352.44 (CaCO3)-0.066(S)0.257(Corg)1.141 with correlation coefficient of 0.983 and with an average standard error of 2.63%.||Journal Article|662|12566|||4|0|1|1994-03-01 0:00:00||||||||||0090-3973||99903509|25 22|3|1994|183-194|JTE9405|Ramsamooj DV|Prediction of Fatigue Life of Plain Concrete Beams from Fracture Tests|experimental verification, fatigue, fracture mechanics, PC concrete, theoretical solution|A mathematical model, based on the principles of fracture mechanics, is proposed for the prediction of the flexural fatigue life of plain concrete beams. The model predictions are compared with about 400 experimental data from four separate collections, published earlier, covering materials with wide ranges of compressive strengths, 20 Mpa to 44.8 MPa, stress range ratios (minimum/maximum bending stress) of 0 to 0.75, and flexing frequencies of 1 to 20 Hz. There is good agreement between the model and the regression lines fitted to the experimental data.||Journal Article|663|12567|||12|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903510|26 22|3|1994|204-211|JTE9405|Jin L-Z, Sandström R|Evaluation of Machinability Data|drilling, machinability, machinability rating, machining operation, materials selection, metal removal rate, milling, turning|Systematic materials selection is essential to fulfill the design criteria. Reliable information on material properties, in turn, is a vital factor for approaching such an objective. The machinability of engineering metals, owing to the marked influence on the production costs, has to be taken into account in the process of materials selection. In an attempt to develop a method for estimating the machinability of engineering metals, machinability data collected from laboratory and literature are assessed. A rating system derived from the metal removal rate is proposed for estimating the relative machinability of carbon and alloy steels, stainless steels, and aluminum, copper, and magnesium alloys.||Journal Article|663|12568|||8|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903511|27 22|3|1994|212-216|JTE9405|Tomesani L|Relevant Errors Associated with Tension Testing of Metals|accuracy, Poisson's ratio, regression analysis, tension test, true stain, true stress, uncertainty, volume change|The problems of properly evaluating the tensile properties of metals are examined. In particular, we estimate the errors introduced by the use of simplified relationships that do not consider the change in specimen volume during the test, and by ordinary regression analysis performed with only one uncertainty-affected variable. Typical values of these errors on different materials are computed by means of tension tests on cylindrical specimens.||Journal Article|663|12569|||5|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903512|28 22|3|1994|217-221|JTE9405|Kang ZQ, Li JB, Wang ZG|Stress Correction for Removal of Material in X-Ray Stress Determination|approximation, double-side removal, power series, shot peening, single-side removal, stress correction, x-ray stress determination|To determine residual stresses in a (flat) plate or bar with a rectangular cross-section by X-ray diffraction after removal of material, we can sectionally approximate the measured stress curve with depth using power series, then consequently evaluate the additional stresses created by removal, and finally obtain the true stress distribution with depth before the layers were removed. Formulas to evaluate corrections for stress have been derived. Two examples demonstrate that power series with few terms can provide us with an approximation good enough for the measured stress curve, and that the influence of the approximation on the corrective result is far less than that of the errors arising from the X-ray stress determination itself.||Journal Article|663|12570|||5|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903513|29 22|3|1994|222-225|JTE9405|Gaskin GB, Pilla GJ, Brown SR|Preparation of Stainless Steel Adherends for Adhesive Bonding|adhesive bonding, floating roller peel test, lap shear tension test, passivation, stainless steel prebonding processes, surface preparation, wedge crack extension test|Adhesively bonded stainless steel aircraft components often fail prematurely at the adhesive/adherend interface. This failure results from exposure of the adhesively bonded joint to various mechanical and thermal stresses, as well as the exposure to hostile environments. Currently, there is not a single, reliable preparation for adhesive bonding that is universally employed for all classes of stainless steel. This study was conducted to evaluate several existing stainless steel prebonding processes, to determine the significant process factors contributing to the adhesive/stainless steel interfacial performance, and to develop a single reliable prebond preparation for stainless steels. Several surface pretreatments were evaluated with various classes of stainless steel. Wedge crack extension test results of moisture conditioned test specimens show that a newly developed pretreatment process yields the most stable passivation surface for various classes of stainless steel.||Journal Article|663|12571|||4|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903514|30 22|3|1994|226-232|JTE9405|Toutanji HA, El-Korchi T|Uniaxial Tensile Strength of Cementitious Composites|alignment, cementitious composites, hydraulic tension tests, uniaxial tension tests, Weibull statistics|A brief review of various methods of measuring the uniaxial tensile strength of cementitious composites is presented. The pros and cons of these methods are described. Common problems associated with the traditional uniaxial tension testing techniques exist, and these problems arise from two areas: (1) stress concentration at gripping and (2) misalignment. These testing artifacts can significantly influence the test results, producing measurements that underestimate the intrinsic strength of the material. A novel approach for testing cementitious composites in tension is described. The test uses cylindrical bar specimens 9.5 mm in diameter and 120 mm in length. The specimens are fractured in a hydraulic chamber which allows specimen self-alignment. The advantages of using the technique are minimization of misalignment and stress concentration, larger specimen volume under stress, and determination of initiation of fracture. The tensile strength values obtained using the hydraulic tension test technique are compared to those obtained by the traditional uniaxial tension tests. The average tensile strength of bigger size specimens, such as 16 mm in diameter and 120 mm in length, was predicted using the application of Weibull theory. Furthermore, these specimens were also tested using the hydraulic tension testing technique. The data show that the predicted values obtained using the application of Weibull theory compare well with the experimental values obtained by the novel tension testing technique.||Journal Article|663|12572|||7|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903515|31 22|3|1994|233-234|JTE9405|Troyanskii AI, Borisenko VA|Temperature Dependencies of Elasticity Characteristics for Tellurium-Alloyed Gallium Arsenide|elastic characteristics, gallium arsenide, precision investigations, temperature, ultrasonic method|The influence of thermal loading on the elasticity characteristics of low-alloyed monocrystalline gallium arsenide has been studied by a precision ultrasonic method in the temperature range from 190 to 380 K. The deviation of the obtained temperature dependencies from some averaged curve is shown to be more appreciable in the first cycle of thermal loading than in subsequent ones.||Journal Article|663|12573|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903516|32 22|3|1994|235-237|JTE9405|Malotky LO|Introduction to the Sixth International Civil Aviation Security Conference (AVSEC '98)||||Journal Article|663|12574|||3|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903517|33 22|3|1994|238-239|JTE9405|Osmus LA|Enforcement of International Regulations|air security, enforcement of U.S. international regulations, International Civil Aviation Organization (ICAO)|Disastrous incidents in international aviation in 1985 prompted the U.S. Congress to pass legislation, The International Security and Development Cooperation Act, to deter crimes against civil aviation. It requires that the Federal Aviation Administration (FAA) assess international airports serving as last points of departure into the United States. The implementation of this law, through the Foreign Airport Assessment Program, yields benefits for both the United States and the host governments assessed. It provides for an exchange between the U.S. government and foreign governments on how to strengthen security procedures; a mechanism for international airports to obtain technical assistance, training, and equipment for the United States; and a way to regulate foreign air carriers.||Journal Article|663|12575|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903518|34 22|3|1994|240-242|JTE9405|Laird DR|Regulation: Perception and Reality|air security, International Civil Aviation Organization (ICAO), passenger profile, positive passenger baggage match, preboard screening|Since the onset of the screening of passengers and their carry-on baggage in 1973 to combat hijackings, the number of hijackings in the United States has been brought to zero. A team effort by the carriers and the Federal Aviation Administration (FAA) played a significant role in the elimination of the problem. Technology developed in the 1970s for airport passenger screening is being pushed beyond its limits in an attempt to detect improvised explosive devices. As we wait for the next generation of technology to appear, we are forced to rely on a combination of overlapping and expensive procedures designed to find the "needle in the haystack." A solution may be the blending of present technologies to meet the threat in aviation today. We must not find ourselves in the situation where the cost of the technologies is not justified in relation to risk. The public will surely be a barometer in this evolving and sensitive process.||Journal Article|663|12576|||3|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903519|35 22|3|1994|243-244|JTE9405|Turner R|Australian System for Aviation Security Identification Cards and Associated Personnel Background Checking|airport security, Australia, aviation security, identification cards, International Civil Aviation Organization (ICAO)|A description is given of the Australian system for aviation security identification cards which authorize persons to be in restricted areas of airports. Considerations in associated background checking of personnel applying for the cards are outlined.||Journal Article|663|12577|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903520|36 22|3|1994|245-246|JTE9405|Joy TJC|Reconciling Passenger Facilitation and Security|air passengers, air security, airports, International Civil Aviation Organization (ICAO), New Zealand|An appropriate balance must be achieved between the efficient movement of passengers through airports and security. Some practical aspects of airport operations to obtain such a balance are discussed.||Journal Article|663|12578|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903521|37 22|3|1994|247-250|JTE9405|Bouisset J-F|Security Technologies and Techniques: Airport Security Systems|air security, airport security, International Civil Aviation Organization (ICAO), training|A description of pertinent text and figures from the revised Chapter 6, "Technologies and Techniques of Security," of the ICAO security manual is provided.||Journal Article|663|12579|||4|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903522|38 22|3|1994|251-256|JTE9405|Sutherland RG|Standardized Training through the Use of the ICAO Standardized Training Packages (STPs)|aviation security, International Civil Aviation Organization (ICAO), training|A discussion of the development of standardized training packages (STPs) for global application in aviation security is presented.||Journal Article|663|12580|||6|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903523|39 22|3|1994|257-258|JTE9405|Wall B|IATA and Its Cooperative Role in Aviation Security|air security, aviation security training courses, aviation terrorism, International Air Transport Association (IATA), International Civil Aviation Organization (ICAO)|The functions and activities of the International Air Transport Association (IATA), the world trade organization of scheduled airlines, particularly in reference to air security, are discussed.||Journal Article|663|12581|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903524|40 22|3|1994|259-264|JTE9405|Koch A|The Role/Responsibility of the Freight Forwarder|air cargo, air security, airports, Civil Aviation Administration-Denmark (CAA-DK), Denmark, International Air Transport Association (IATA), International Civil Aviation Organization (ICAO)|Security measures related to the handling of air cargo are outlined, and the responsibilities of policing authorities, airports and airlines, and freight handlers are made clear, within the context of Danish law and the Danish Civil Aviation Administration.||Journal Article|663|12582|||6|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903525|41 22|3|1994|265-266|JTE9405|Forbes D|The Need to Harmonize Cargo Security Rules|air security, indirect carriers, International Civil Aviation Organization (ICAO)|The International Civil Aviation Organization (ICAO) has not been able to influence world governments sufficiently to bring about universal support for Annex 17 security measures governing air cargo. The industry, notably the indirect carriers, view government regulatory plans as unrealistic and unconvincing, because of inconsistencies and extremes in the application of Annex 17 principles. The resultant lack of progress could be countered by uniting government and industry within the middle ground of compromise, and by providing ICAO with the machinery to help administrations introduce harmonized practices.||Journal Article|663|12583|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903526|42 22|3|1994|267-274|JTE9405|Polski PA|International Aviation Security Research and Development|aircraft hardening, airport security, explosives detection, Federal Aviation Administration (FAA), human factors, International Civil Aviation Organization (ICAO), weapons detection|A discussion of the research and development activities with the U.S. Federal Aviation Administration (FAA) related to aviation security, based on the principles of (1) denying access; (2) weapons/explosives detection; (3) human factors; and (4) aircraft hardening, is presented.||Journal Article|663|12584|||8|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903527|43 22|3|1994|275-276|JTE9405|Draghetti PM|Aviation Security Standards Development within ASTM Committee F-12 on Security Systems and Equipment|ASTM Committee F-12, aviation security, International Civil Aviation Organization (ICAO)|The structure and objectives of ASTM Committee F-12 on Security Systems and Equipment are described, with emphasis on its active components which involve aviation security. Pertinent existing standards and standards under development are discussed, particularly those within Subcommittees F12.10 on Systems, Products and Services, F12.50 on Locking Devices, and F12.60 on Controlled Access Security, Search and Screening Equipment||Journal Article|663|12585|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903528|44 22|3|1994|277-279|JTE9405|Cartwright N|Reaching Consensus on Technical Standards through ICAO: The Work of Ad Hoc Group of Specialists on the Detection of Explosives|air security, explosives detection, International Civil Aviation Organization (ICAO), plastic explosives|The ICAO Ad Hoc Group of Specialists on the Detection of Explosives was responsible for the preparation and monitoring of the technical annex for the recently signed International Convention on the Marking of Plastic Explosives for the Purposes of Detection. It is also currently developing protocols and standards for the testing and evaluation of explosives detection equipment. Under the umbrella of ICAO the group has developed an approach that has very successfully dealt with the challenge of consensus building in this specialized area of new technology and rapidly evolving capability.||Journal Article|663|12586|||3|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903529|45 22|3|1994|280-281|JTE9405|Elias L|Development of Trace Explosive Detection Standards|air security, International Civil Aviation Organization (ICAO), particle detection, trace explosives, vapor detection|The task of defining detection standards for trace explosive detectors, similar to those used with bulk detectors, is not straightforward. Difficulty arises because the relation between the mass of concealed explosive within a package and the quantity of telltale vapor or other trace residue around the exterior of the package is not predictable. Nevertheless, it is possible to formulate meaningful test procedures that can be used to quantify detector performance in terms of minimum detectable trace levels. Such test procedures, outlined here, could be useful in establishing detection criteria for evaluation or certification purposes.||Journal Article|663|12587|||2|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903530|46 22|3|1994|282-285|JTE9405|Hnatnicky S|Selection and Use of Explosives Detection Devices to Check Hand-Held Luggage|air security, airport security, BKA, explosives vapor detection, International Civil Aviation Organization (ICAO)|A comparison of four explosives detection devices of use in airport security for the checking of carry-on luggage is presented.||Journal Article|663|12588|||4|0|1|1994-05-01 0:00:00||||||||||0090-3973||99903531|47 22|4|1994|291-301|JTE9407|McKeighan PC, Smith DJ|Determining the Potential Drop Calibration of a Fatigue Crack Growth Specimen Subject to Limited Experimental Observations|calibration errors, crack length errors, fatigue crack growth (FCG), potential drop (PD), variability of fatigue data|Six separate calibration techniques are applied to potential drop (PD) and crack length data from 23 experimental datasets. Five of the techniques use limited experimental input gained during precracking and after test completion to derive the coefficients associated with the calibrations. The datasets include SE(B) and M(T) specimens, fatigue crack growth (FCG) tests and foil analog simulations as well as various aluminum alloys and steel. A comparison of the calibration techniques is undertaken in terms of crack length and the subsequent effect on stress intensity factor errors. The best calibration techniques using two PD and crack length data pairs are the two-point modified and post-test corrected Johnson's equation. Using these methods, 21 of the 23 tests satisfy a criterion based on an acceptable ±2% mean variation in stress intensity factor. If a statistical assessment of the data is made, only 30 to 35% of the tests satisfy this criterion. Finally, the crack length prediction errors that result from the different calibrations can typically cause a 15 to 30% variation in FCG rate da/dN at a given DK level. This difference is found to be primarily due to errors in the DK calculation.||Journal Article|664|12589|||11|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903532|48 22|4|1994|302-308|JTE9407|Srinivas M, Kamat SV, Rao PR|A Fractographic Technique for the Estimation of Initiation Fracture Toughness JIc for Ductile Materials|JIc, blunt notch, single specimen, stretch zone width|A single specimen fractographic technique based on critical stretch zone width measurements is suggested for the estimation of fracture toughness (JIc) for highly ductile materials. The salient feature of this technique is that it overcomes the problem of fatigue precracking and is able to predict the fracture toughness of a material using a blunt notch specimen. Fracture toughness tests on commercially pure Armco iron, nickel, and aluminum as well as Al-Mn based austenitic stainless steel and En28 steel were carried out to validate the method.||Journal Article|664|12590|||7|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903533|49 22|4|1994|309-317|JTE9407|Kobayashi T, Shockey DA, Ogundele G, McNabb DD, Sidey D|Deducing Crack History in an Aged Boiler Tube from Fracture Surface Topography|aging systems, boiler tubes, crack growth rate, crack history, crack initiation time, fractography, FRActure Surface Topography Analysis (FRASTA)|A new fractographic technique, FRActure Surface Topography Analysis (FRASTA), was applied to a crack in a boiler tube of a fossil-fired power plant in an attempt to determine when in its 22-year service history the crack initiated and the rate at which it grew. By comparing the topographies of the conjugate crack surfaces, we estimated that the crack nucleated about 68 000 h after onset of service and experienced several periods of accelerated and decelerated growth with rates ranging from 5 × 10-5 to 9.5 × 10-5 mm/h. These findings correlated roughly with chemical cleanings and startup/shutdown cycles. A similar analysis of a corrosion fatigue specimen tested under controlled conditions in the laboratory provided results consistent with measured values. These results suggest that fractography can be used to extract valuable information on cracking kinetics in aged systems and, thereby, lead to new ways to predict, monitor, and extend component life.||Journal Article|664|12591|||9|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903534|50 22|4|1994|318-326|JTE9407|Murakami Y, Toriyama T, Coudert EM|Instructions for a New Method of Inclusion Rating and Correlations with the Fatigue Limit|fatigue strength, high strength steel, inclusion rating, square root of projection area (???area), statistics of extreme, Vickers hardness|Many inclusion rating methods already exist [16], some of which have been adopted as the standards for particular countries or industries. However, with the existing methods, it is difficult to evaluate the relationship between the fatigue limit and the type, size, or distribution of the inclusions. Recent works have shown that inclusions behave as small defects and that the quantitative effect on the fatigue strength can be assessed from an evaluation of the square root of the projected area of the largest inclusion, on a plane perpendicular to the maximum principal stress direction. This parameter, designated ???areamax, contained in a definite volume, can be evaluated using the statistics of extremes of the inclusion distribution.||Journal Article|664|12592|||9|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903535|51 22|4|1994|327-334|JTE9407|Kumar AM, Hirth JP, Hoagland R, Feng X|A Suggested Test Procedure to Measure Mixed Mode IIII Fracture Toughness of Brittle Materials|fracture, mixed mode toughness, stress intensity factor, toughness|This article describes a test procedure to measure mixed mode IIII fracture toughness. The traditional compact tension specimen geometry is modified to include an angled crack slot. This angle is varied to produce various mode I/mode III ratios. A further modification to the specimen design involving two crack fronts in a triple "pantleg" configuration that can produce near mode III loading at the crack tip is also described. Together, these two specimens can be used to test the entire spectrum of combined mode IIII. Results of mixed mode fracture tests on 2034 aluminum alloys using these specimens are presented. A three-dimensional (3-D) finite element model of the modified compact specimen to validate the analytical procedure is also described. Angular correction factors for the mixed mode case are also presented. The results indicate the feasibility of developing a new standard test method to measure mixed mode fracture toughness in macroscopically brittle metallic materials.||Journal Article|664|12593|||8|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903536|52 22|4|1994|335-342|JTE9407|Rodríguez J, Navarro C, Sánchez-Gálvez V|Numerical Assessment of the Dynamic Tension Test Using the Split Hopkinson Bar|dynamic tests, Hopkinson bar, numerical modeling|An experimental and numerical analysis of tension tests in the Hopkinson bar is made to assess the suitability of this method to characterize materials in tensile conditions at strain rates about 1000 s-1. The stress and strain fields that appear in the specimen are analyzed by the finite element method. This mathematical simulation of the test allows a check of the hypotheses normally used in obtaining results: equilibrium situation and uniform strain distribution in the specimen. The simulation process also provides some criteria to design the experimental setup and the specimen geometry for the best agreement with the ideal situation. Finally, because of the usual assumption regarding the uniformity of the strain distribution in the specimen may not be valid, some corrections are suggested to obtain reliable material properties from direct test results in different situations.||Journal Article|664|12594|||8|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903537|53 22|4|1994|343-350|JTE9407|Cios KJ, Baaklini GY, Vary A, Tjia RF|Radial Basis Fanction Network Learns Ceramic Processing and Predicts Related Strength and Density|ceramics, neural networks, silicon nitride|Radial basis function (RBF) neural networks were trained using the data from 273 Si3N4 modulus of rupture (MOR) bars that were tested at room temperature and 135 MOR bars that were tested at 1370°C. Milling time, sintering time, and sintering gas pressure were the processing parameters used as the input features. Flexural strength and density were the outputs by which the RBF networks were assessed. The "nodes at data points" method was used to set the hidden layer centers and output layer training used the gradient descent method. The RBF network predicted strength with an average error of less than 12% and density with an average error of less than 2%. Further, the RBF network demonstrated a potential for optimizing and accelerating the development and processing of emerging ceramic materials.||Journal Article|664|12595|||8|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903538|54 22|4|1994|351-359|JTE9407|Larralde J, Silva-Rodriguez R, Burdette J, Harris B|Bond Tests of Fiberglass-Reinforced Plastic Bars in Concrete|bond strength, bond test, concrete reinforcement, fiberglass reinforced plastics, pullout test, reinforced composites, reinforced plastics, slip|Fiberglass Reinforced Plastic (FRP) bars for concrete reinforcement have been commercially available for several years. The main advantage of such bar relative to the conventional steel reinforcing bars is their resistance to corrosion. The reinforced plastic bars are slightly different from the conventional steel bars both geometrically and mechanically. Thus, research is needed to understand their behavior and to be able to use them in concrete reinforcement with adequate reliability. Bond strength of reinforced plastic bars in concrete is one of the mechanical and behavioral differences with the steel bars. This paper presents the results of pullout and beam tests conducted to determine the bond stress-slip behavior of FRP bars in concrete.||Journal Article|664|12596|||9|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903539|55 22|4|1994|360-364|JTE9407|Häberle JG, Matthews FL|The Influence of Test Piece Preparation on the Compressive Strength of Unidirectional Fiber-Reinforced Plastic|compression testing, fiber-reinforced plastics, specimen preparation|During a wide-ranging experimental study of compression testing of unidirectional fiber-reinforced plastics (FRP), covering several materials and test methods, it became apparent that the variability of data could be reduced by adopting a rigorous and consistent approach to all phases of specimen production. Details are given of the procedures adopted, together with results from an associated parameter study.||Journal Article|664|12597|||5|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903540|56 22|4|1994|365-369|JTE9407|Trindade AC, Cavaleiro A, Fernandes JV|Estimation of Young's Modulus and of Hardness by Ultra-Low Load Hardness Tests with a Vickers Indenter|diagonal length, extruded lip, indentation depth, offset, ultra-low load hardness, unloading, Vickers hardness, Young's modulus|The evaluation of the elastic-plastic properties of a material by using an ultra-low load hardness test requires a geometrical calibration that must take into account the imperfect form of the diamond indenter. In the present work, the Vickers indenter offset of the microindentation equipment was estimated using differently heat-treated steel samples. To this end, the dimensions of the indentations have been evaluated by two different methods: optical measurement of the diagonals and direct measurement of the penetration depth during the test. The elastic-plastic properties are then calculated from the analysis of the penetration depth/indentation load curves. The Young's modulus values determined for the different high-speed steel samples were very similar and close to the literature value for steel if the appropriate corrections are performed. The hardness values decrease when the determination procedure includes the geometrical correction of the indenter offset, and still further when using the total correction obtained by means of optical measurements of the indenter diagonal. Variation of the hardness values with the applied load is much less when the corrections are carried out.||Journal Article|664|12598|||5|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903541|57 22|4|1994|370-375|JTE9407|Salawu OS, Williams C|An Excitation System for Dynamic Testing of Large Structures|dynamic testing, exciters, full-scale testing, vibration, vibrators|The service behavior and real performance of engineering materials and systems are best evaluated using data obtained from prototype or full-scale testing, or both. For large engineering structures composed of materials such as concrete, with variable properties, data from such tests are invaluable. Full-scale forced vibration testing is a useful tool for obtaining information on the condition of structural systems. As compared to ambient vibration testing, forced vibration testing can provide more accurate estimates of damping capacity and yield data from which better system identification of structural parameters is possible. However, full-scale forced vibration field testing is much more difficult to achieve when compared with laboratory tests on prototypes. The (large) size of the structure usually means special excitation systems are required. The development and performance characteristics of such an excitation system is described in the article. The system consists of an hydraulic actuator, mounted within a purpose built frame, two pumps, an electronic control unit, and a personal computer. It can be used to induce vertical excitation of highway bridges, long-span floor slabs, and similar structures.||Journal Article|664|12599|||6|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903542|58 22|4|1994|376-382|JTE9407|Pellicane PJ, Bodig J, Mrema AL|Modeling Wood in Transverse Compression|compression perpendicular-to-grain, experimental verification, finite element method, wood|A plane-stress, finite element model has been developed to predict the stress distribution in wood members subject to perpendicular-to-grain compression. This model exploits linear-strain, isoparametric triangular elements used in sufficient number to achieve a convergent solution. Model verification was achieved through comparison of numerically obtained deformation predictions with corresponding experimental data obtained from actual test specimens. Twenty-seven specimens were instrumented to determine their deformations at numerous locations. Test materials were sampled from three logs (two engelmann spruce, one western hemlock). Specimens were fabricated with three widely different orthotropic ratios, three geometries (length/depth ratios), and three loading geometries (uniformly distributed load across the entire length, one-half length, and one-quarter length). In total, 377 experimental measurements on 27 specimens were compared to finite element predictions. The results showed that on average the model predicted local deformation to within 5%.||Journal Article|664|12600|||7|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903543|59 22|4|1994|383-387|JTE9407|Pellicane PJ, Bodig J, Mrema AL|Behavior of Wood in Transverse Compression|compression perpendicular to grain, finite element model, loading geometry, orthotropic ratios, sensitivity analysis, specimen geometry, wood|A finite element analysis program exists to evaluate the stress distribution in wood members subjected to perpendicular-to-grain (transverse) compression. In this study, the program was used to perform parameter studies to evaluate the effects of key variables on the distribution of stresses and the maximum stress concentrations in wood subjected to transverse compression. These variables included: specimen geometry (length/depth), loading geometry (loaded length/specimen length), and material properties (ratio of moduli of elasticity of the wood in the direction of loading/perpendicular to loading). The results showed that a complex state of stress exists in members even when the load is distributed over the entire specimen surface. In particular, numerically-determined stresses nearly 3.5 times the nominal stress were found for certain combinations of input parameters. In addition, an empirically-derived equation is presented that estimates the magnitude of maximum stress concentration as a function of the three parameters investigated. The equation was developed with the use of multiple regression techniques and had a correlation coefficient of 0.958.||Journal Article|664|12601|||5|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903544|60 22|4|1994|388-396|JTE9407|Ajayi JO, Elder HM|Objective Evaluation of Surface Characteristics to Determine Smoothness of Pile Fabrics|amplitudes, contour, friction, peaks, pile, pitch, roller, smoothness, stick-slip, stylus|Measurements of surface characteristics of pile fabrics by various methods to determine surface smoothness is reported. It is demonstrated that the number of peaks detected by methods using a roller, stylus, and friction traces is the best indicator of fabric smoothness. A negative correlation between this quantity and smoothness suggests that fabrics that yield more peaks are likely to be smoother than those with fewer peaks. This also agrees broadly with the results of friction measurement, lateral air flow, and microscopic measurements. Subjectively, judges found fabrics readily identifiable, but finding the right descriptive adjective for these differences remains a problem.||Journal Article|664|12602|||9|0|1|1994-07-01 0:00:00||||||||||0090-3973||99903545|61 22|5|1994|401-409|JTE9409|Tang T|Effects of Load-Distributed Width on Split Tension of Unnotched and Notched Cylindrical Specimens|crack, displacement, finite element analysis (FEA), fracture mechanics, load, split tension, stress, stress intensity factor, tensile strength|Unnotched and notched cylinders in split tension are analyzed. The load-distributed width has been shown to affect the stress and displacement distributions. Based on finite element analysis, linear elastic fracture mechanics (LEFM) formulas for the stress intensity factor K1, crack mouth opening displacement (CMOD), and the crack opening displacement (COD) profile for the split tension of notched cylinders are first provided in terms of load-distributed width as well as load magnitude, specimen size, and notch length. A formula expressing the effect of load-distributed width on maximum tensile stress in an unnotched cylinder is also provided.||Journal Article|665|12603|||9|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903546|62 22|5|1994|410-419|JTE9409|Riemslag AC|Fatigue Testing of High-Density Polyethylene and Polycarbonate with Crack Length Measurement Using Image Processing Techniques|crack growth mechanisms, crack length measuring, fatigue crack growth, image processing, polycarbonate (PC), polyethylene (PE)|A new automated method of measuring fatigue cracks in polymers is discussed. The new method is based on a video signal of the crack which is analyzed with "image processing" techniques. With this technique the crack length is measured every 20 s during a fatigue test. The accuracy of one single measurement is about 0.05 mm, but this can be increased by averaging a large number of measurements. The applied automated data collection and subsequent data processing is discussed in relation to the recommendations given in ASTM E 647, Test Method for Measurement of Fatigue Crack Growth Rates. The use of the new technique is illustrated on the basis of fatigue tests performed on transparent polycarbonate (PC) and nontransparent polyethylene (PE). The fatigue behavior of PE and PC is briefly discussed.||Journal Article|665|12604|||10|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903547|63 22|5|1994|420-423|JTE9409|Pecorini TJ, Moskala EJ|The Influence of Testing Methodology on the Fatigue Crack Propagation Behavior of Cellulose Esters|K-decreasing, K-gradient, cellulose-acetate-propionate (CAP), crazing, fatigue, shear yielding|In the fatigue crack propagation behavior of cellulose esters, a crazing mechanism controls growth at low stress intensity (DK) levels while a plane-strain-shear yielding mechanism becomes dominant at higher DK values. The growth rate associated with the transition between these two mechanisms has been found to be a function of the material's yield strength. Most recent data have shown that the onset of this transition is also related to the test methodology. Constant-load-amplitude, K-increasing tests produce the most conservative (highest fatigue rate) values for the transition, whereas with decreasing stress intensity tests, the transition occurs at much lower growth rate values. It is important to note, however, that test methodology does not affect the relation between crack growth rate and DK when growth is dominated by only a single mechanism.||Journal Article|665|12605|||4|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903548|64 22|5|1994|424-430|JTE9409|Harvey J, Mills T, Scheffy C, Sousa J, Monismith CL|An Evaluation of Several Techniques for Measuring Air-Void Content in Asphalt Concrete Specimens|air-void content, asphalt-concrete, bulk specific gravity, fatigue beam, paraffin wax, simple shear test, specimen preparation|Precise and accurate measurement of air-void content is critical to the evaluation of asphalt-aggregate mix specimens taken in the field or compacted in the laboratory. It is an integral part of the performance-based testing and analysis methods developed by the Strategic Highway Research Program Contract A-003A (SHRP A-003A). Standard methods for drying specimens after coring and/or cutting from a larger compacted mass, and for measuring bulk specific gravity present problems for testing of the same specimen using equipment developed by SHRP A-003A, or whenever the specimen must be fixed to the testing equipment by means of an adhesive. This paper presents a comparison of the standard methods of air-void content measurement, measurement of bulk specific gravity using unsealed specimens and using specimen sealed with paraffin wax (ASTM D 1188, Test Method for Bulk Specific Gravity and Density of Compacted Bituminous Mixtures Using Paraffin-Coated Specimens), with three alternative methods for sealing the specimen: dusting with zinc stearate powder, wrapping with a waxy elastic paper called Parafilm™ (American National Can), and covering with a rubber membrane. The results indicate that each of the methods produces different measured air-void contents. The waxy elastic paper results were closest to those obtained from specimens sealed with paraffin, and it is suggested that this is a suitable alternative to paraffin wax when the specimens have smooth (cut/cored) surfaces and are to be tested for performance afterward. The use of an air gun to dry specimens after coring and/or cutting was compared with the standard oven-drying method (ASTM D 2728, Practice for Paving Uses and Application Temperatures for Road Tars). It was found that the use of a 210 kPa (30 psi) air gun produced similar results to those found with the standard method and was nondestructive, thus allowing further testing of the specimen.||Journal Article|665|12606|||7|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903549|65 22|5|1994|431-441|JTE9409|Svenson AL, Hargrave MW, Bank LC, Ye BS|Data Analysis Techniques for Impact Tests of Composite Materials|composite materials, energy absorption, glass fiber reinforced plastics, impact testing, normalization|This paper discusses data analysis techniques for instrumented impact tests conducted on glass fiber composite materials. For this study, a drop weight tower has been instrumented with an accelerometer and computer data acquisition system. From the acceleration data obtained, load, energy, velocity, and displacement are calculated in a spreadsheet environment. The resulting data from multiple tests for each material type considered are then averaged producing average plots. The standard deviation is also calculated and plotted for the load data. These curves are then used to characterize the impact behavior of the material. Also introduced is a procedure by which results are normalized by all geometric parameters present in the impact test. This method provides for comparison of test data from three-point bend impact tests having differing geometric parameters.||Journal Article|665|12607|||11|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903550|66 22|5|1994|442-448|JTE9409|Carey RF|A Differential Air Deflation Quality Assurance Test for Surgical Gloves|air deflation test, gloves, leakage test, quality assurance (QA)|A new quality assurance (QA) test for surgeon's gloves is described which uses a sensitive differential pressure gage to detect glove holes as small as 0.020 mm. The test can be performed quickly and without damage to the glove. Standard holes in nickel masks, ranging in diameter from 0.015 mm to 0.10 mm, were used to calibrate test sensitivity. Air pressure losses in test gloves were compared directly to air pressure in an intact glove. Holes in glove fingers and in glove palms were made with an excimer laser and also with an acupuncture needle. These gloves were then tested with this differential air deflation test and with the standard 1000 mL water fill test. The new test offers similar test sensitivity to the 1000 mL test and, in addition, offers the possibility of quantitative leak testing.||Journal Article|665|12608|||7|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903551|67 22|5|1994|449-452|JTE9409|Rodak EM, Taylor RJ, Hirsch DB, Linley LJ|Effects of Sample and Test Variables on Electrical Wire Insulation Flammability|flammability, oxygen-enriched atmospheres, test methods, wire insulation|A new test method has been adopted to evaluate the flammability of electrical wire insulation materials. In this test, wire insulation is exposed to an external ignition source while the electrical conductor is internally heated by an electric current. The repeatability of the test and the effects of wire gage and insulation thickness, internal wire temperature, and sample orientation on the wire insulation flammability were evaluated. Experimental results showed that the new test is a practical and repeatable method for evaluating flammability of wire insulation materials.||Journal Article|665|12609|||4|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903552|68 22|5|1994|453-459|JTE9409|Mahendran M|Effect of Overload Cycles on Thin Steel Roof Claddings during Cyclonic Winds|experiments, fatigue, finite element analysis, overload cycles, small scale models, steel roof claddings|During an investigation on thin steel roof claddings under simulated cyclonic wind loading, it was found that trapezoidal roof claddings behaved quite differently to corrugated (arc and tangent type) roof claddings due to the presence of overload cycles. The overload cycles caused a reduction in fatigue life for corrugated roofing whereas the reverse occurred for trapezoidal roofing. This contrasting behavior of the two crest-fixed roof claddings was investigated using small scale roofing models instead of the commonly used large scale two-span roof claddings. It was found that overload cycles formed a weaker locally dimpled mechanism around the fastener holes of corrugated roofing and thus accelerated the fatigue-caused pull-through failure. In contrast, a stronger deformed shape was formed in trapezoidal roofing which delayed the pull-through failure. Both laboratory testing and finite element analysis of small scale models were used to study the contrasting behavior of roof claddings.||Journal Article|665|12610|||7|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903553|69 22|5|1994|460-464|JTE9409|Martínez JA, Kugler HP, Merino S, Drude H, Criado AJ|Mechanical Study of a Hypoeutectoid Steel Weld|data evaluation, mechanical properties, steels, tension testing, welding|A comparative study was made of the mechanical behavior of the different zones in a welded joint of hypoeutectoid steel, using the uniaxial tension test supported by other conventional techniques. Applying the optoelectronic method to recording and analyzing the results of a tension test gives the distribution of the deformations produced in a test-piece and shows the plastic properties of each zone in one sole experiment.||Journal Article|665|12611|||5|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903554|70 22|5|1994|465-469|JTE9409|Ajayi JO, Elder HM|Comparative Studies of Yarn and Fabric Friction|capstan, fabrics, friction, knitting, linear, relaxation, scouring, tension, yarns|A comparison of the magnitudes of yarn-to-yarn and fabric-to-fabric friction is made. It is shown that yarn friction measured on a capstan (cylindrical) surface is significantly greater than that measured on a flat surface. The greater magnitude of the coefficient of friction in a capstan assembly is ascribed to the effects of experimental variables such as capstan radius, angle of lap, and input tension. The coefficient of friction of fabrics is also shown to be greater than that of their component yarns. Yarns with higher frictional properties yield fabrics whose frictional properties are also higher.||Journal Article|665|12612|||5|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903555|71 22|5|1994|468|JTE9409|Wood FW|Introduction to the Symposium on Case Studies of Wear-Related Failure Analyses||||Journal Article|665|12613|||1|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903556|72 22|5|1994|472-475|JTE9409|Wood FW|Summary on the Role and Analysis of Wear in Failures|abrasion, adhesive wear, cavitation, erosion, failure analysis, surface damage, wear|An overview of the meaning of wear, how it occurs, its involvement in failures, and how it can be detected and evaluated is presented. Relevant definitions, surface characteristics, detrimental consequences, and techniques for investigation and analysis are reviewed. The intentions are to provide a basis for interrelating the case histories presented at the Symposium on Wear-Related Failure Analyses, and, together with the more specific case histories, to heighten the realization of the role that wear plays in many failures.||Journal Article|665|12614|||4|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903557|73 22|5|1994|474-484|JTE9409|Milligan HL, Johnson BM, Engel PA|Wear Analysis of Björk Shiley Delrin Tilting Disc Heart Valves|Delrin, heart valves, impact wear, wear analysis, wear rate, wear testing|Prosthetic heart valves must open and close 40 million cycles annually, year in and year out, in a biochemically active and corrosive medium and without benefit of periodic maintenance. Examination of explanted Björk-Shiley Delrin Heart Valves revealed that some valves developed wear grooves in the Delrin occluder disc from contact with the inlet strut. With Delrin Heart Valve implant durations reaching 20 or more years, studies were initiated to fully analyze the wear of explanted valves. Delrin discs from 15 explanted valves with implant durations of up to 20 years (800 million cycles of operation) were dimensionally inspected; the wear features and profiles measured by stylus profilometer and optical comparator; wear surfaces mapped by Moiré shadow interferometry; and the surfaces examined by scanning electron microscope. Pulsatile flow heart valve simulator studies were conducted to determine valve disc impact velocity and impulsive force-time characteristics. Material tests were conducted on circa 1970 Delrin coupons to determine the wear-related physical properties of the Delrin disc. These investigations cast light upon the wear behavior of Delrin occluder discs, and hence their effects upon valve performance and valve life could be evaluated. The wear phenomenon as seen on clinically explanted valves can be attributed to percussive impact wear concepts. The wear depth from this mechanism is shown to be a logarithmic function with respect to cycles and time. The amount of wear observed on the periphery of the explanted Delrin discs returned to date suggests that clinically significant increases in valve regurgitation in implanted valves has not likely occurred. Disc retention safety margin appears not to be substantially affected. In conclusion, wear of the disc in the 15 Björk-Shiley Delrin Heart Valves in this study does not appear to be a factor affecting valve life.||Journal Article|665|12615|||11|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903558|74 22|5|1994|485-489|JTE9409|Budinski KG|Scoring of Precision Spur Gears|galling, gear wear, gears, scoring, scuffing|A group of manufacturing machines employed precision spur gears as the timing mechanism for machine operations. These machines had worked successfully for about ten years with little or no problems with gear wear or deterioration. When new machines were brought on line with recently made gears there were immediate problems with gear tooth scoring. A laboratory study was conducted to determine if metallurgical conditions were related to the gear scoring. Recent gears were made from a modification of the alloy used in early gears. The new alloy had been modified to make it more resistant to softening in coating operations. Reciprocating wear tests and galling tests were conducted to compare the tribological characteristics of the old and new gear steels. It was determined that the threshold galling stress of the gear steels was strongly dependent on the hardness. The reciprocating wear tests indicated that the wear resistance was affected by the volume fraction of hard phases in the steels. The recommended short-term solution was to alter the tempering procedure for the steel to keep Rockwell C hardness above 60; the long-term solution was to change the gear material and lubrication.||Journal Article|665|12616|||5|0|1|1994-09-01 0:00:00||||||||||0090-3973||99903559|75 22|6|1994|505-511|JTE9411|Wilson CD, Landes JD|Inconsistencies between CTOD and J Calculations|J-integral, crack-tip opening displacement (CTOD), fracture toughness, plastic hinge model, power law hardening|Crack-tip opening displacement (CTOD) determined using the plastic hinge model included in the ASTM E 1290 (Test Method for Crack-Tip Opening Displacement (CTOD) Fracture Toughness Measurement) is inconsistent with CTOD determined using the ASTM E 813 (Test Method for JIc, Measure of Fracture Toughness) combined with an equation relating J to CTOD. The plastic hinge model is also inconsistent with the EPRI handbook estimation scheme. The plastic hinge model is highly inaccurate for hardening materials. To explore these inconsistencies, the EPRI scheme was used to generate theoretical load-displacement curves of a compact tension (CT) specimen for a wide range of materials and crack sizes. An alternate equation, derived for a power law hardening material, is shown to be consistent with both the ASTM E 813 and the EPRI handbook estimation scheme. The alternate equation accounts for nonlinearities in the relationship between CTOD and plastic load-line displacements. Differences between the alternate equation and the EPRI scheme are discussed. Experimental results demonstrate the inaccuracy of the plastic hinge model and the accuracy of the power law model.||Journal Article|666|12617|||7|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903560|76 22|6|1994|512-516|JTE9411|Shaw WJD, Zhao W|Back Face Strain Calibration for Crack Length Measurements|back face strain, compliance, crack length, crack measurement, fatigue crack length|A new calibration of back face strain (BFS) versus crack length a was developed. The calibration incorporates crack closure effects and is based upon a least squares multiple curvilinear regression analysis using seven specimens. Fatigue crack growth took place over a range of crack length to width ratios a/W from 0.2 to 0.8. The information was obtained under constant change in stress intensity factor DK using compact fracture toughness specimens of 2024-T351 aluminum alloy. In addition, two regular fatigue life crack propagation test conditions were used in the analysis database. The calibration function A*(a/W) is presented in a tabular form as well as in a polynomial equation format. The physical crack length was measured on both surfaces and later, after fracture, corrections of crack length were made for both curvature and plastic zone size. No effect of DK and specimen thickness on the calibration behavior was found to occur. The calibration equation was checked against crack lengths during fatigue crack growth behavior of both HSLA steel and mechanically alloyed aluminum materials and was found to he accurate.||Journal Article|666|12618|||5|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903561|77 22|6|1994|517-521|JTE9411|Rinnovatore JV, Lukens KF, Reinhold J, Mahon W|Charpy Transition Studies of an Embrittled AISI 8640 Lower Bainitic Steel|8640 alloy steel, arsenic, bainite, Charpy impact, embrittlement, phosphorus, transition temperature|A study was performed of the effects of phosphorus and arsenic as embrittling agents on the Charpy impact behavior of resulfurized AISI 8640 steel. The steel was heat-treated to several bainitic and one martensitic condition with a wide range of strength levels. Charpy transition temperature curves were developed for each condition. SEM fractography was used to analyze the fracture behavior of the various heat-treated structures. The results show that AISI 8640 steel with high phosphorus and high arsenic was embrittled in the low-strength bainitic condition as well as in the high-strength martensitic condition. Embrittlement was evidenced by low Charpy impact energies, increased transition temperatures, and an intergranular fracture mode.||Journal Article|666|12619|||5|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903562|78 22|6|1994|522-529|JTE9411|Beghini M, Bertini L, Raffaelli P|Numerical Analysis of Plasticity Effects in the Hole-Drilling Residual Stress Measurement|finite elements, hole-drilling method, measurement, plasticity, residual stress|The aim of this work was to analyze the effect of plasticity on residual stress measurement when the through thickness center-hole technique is used. The study investigated the effect of the most important loading, measuring, and material parameters, i.e., the residual stress intensity, the ratio between the principal residual stresses, the orientation of the strain-gage rosette with reference to the residual stress principal directions, the yield strength, and the strain hardening characteristics of the material. By means of a finite element simulation of the measurements, the errors that are usually produced by the direct use of ASTM E 837 (Test Method for Determining Residual Stresses by the Role-Drilling Strain Gage Method) for the elaboration of the rosette strain gage readings was firstly determined by considering large enough ranges of the above-mentioned parameters to represent many conditions of practical concern. Afterwards it was shown that, at least within the limit of validity of the model, a considerable reduction of those errors can be obtained by using the proposed analytical procedure for elaborating the readings of a classical three elements strain-gage rosette. Moreover, the use of a new type of rosette with four radially oriented strain gages was proposed which could lead to further improvement of the measurement accuracy in any considered condition.||Journal Article|666|12620|||8|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903563|79 22|6|1994|530-536|JTE9411|Field DP, Sample VM, Rader RS|Determination of Softening Kinetics in a Material by Measuring the Evolution of Hot Flow Stress|aluminum, recovery, recrystallization, static softening|A new technique for estimating the time and temperature-dependent softening response of a deformed material is proposed. The hot flow stress is measured at various intervals in a quasistatic softening experiment to determine the kinetics of softening. A major advantage of the proposed technique is that a single specimen can be used to estimate the evolution of softening without having to cool and reheat the specimen for each measurement. High resolution strain measurement apparatus is used in the experiments, as minimizing strain is a critical requirement in properly performing the measurement. Test control requires optimal performance from the servohydraulic system which must operate near its threshold for reliable information to be obtained. Experimental results indicate that age hardening response as well as recovery and recrystallization kinetics can be measured using this method.||Journal Article|666|12621|||7|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903564|80 22|6|1994|537-541|JTE9411|Rosenberg HS, Syrett BC|Electrochemical Impedance Spectroscopy for Monitoring Coating Performance in Condensing Environments|coating performance, condensing environment, electrochemical impedance spectroscopy (EIS), flue gas desulfurization (FGD), organic linings, test method|A novel method is described for monitoring coating performance in the thin liquid films found in condensing environments, such as in the corrosive condensate found in flue gas desulfurization (FGD) systems. The method involves exposing coated metal panels to controlled environments, created by atomizing solutions of appropriate composition, in fog chambers. The fog deposits on the coated surface as a thin film that simulates the condensate formed in actual service. The performance of the coatings is monitored in situ by electrochemical impedance spectroscopy (EIS) during periods when the exposed coated surfaces are temporarily flooded with bulk solution having the same composition as the condensate. The method has been used to evaluate the effects of sixteen environmental factors on the performance of eight coatings currently used in FGD outlet ducts.||Journal Article|666|12622|||5|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903565|81 22|6|1994|542-547|JTE9411|Dolan JD|Proposed Test Method for Dynamic Properties of Connections Assembled with Mechanical Fasteners|cyclic, damping, ductility, dynamic, equivalent-energy, mechanical connections, sequential-phased displacement|A new test procedure for connections assembled with mechanical fasteners is presented. The procedure provides information on cyclic and dynamic characteristics that will allow the relative performance of connections manufactured with different materials to be directly compared. An equivalent energy elastic-perfectly plastic system is defined that allows comparison of initial stiffness, yield load, and ductility on an equivalent basis. The hysteretic and equivalent viscous damping are also determined to provide information on the energy dissipation characteristics of the connection. Adoption of this test procedure will provide information that will allow engineers and architects to evaluate the performance of competing materials with direct comparisons. It will also provide uniform data from which revisions to the model building codes and design specifications for each material can be made on an equivalent basis.||Journal Article|666|12623|||6|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903566|82 22|6|1994|548-555|JTE9411|Taves LBS|An Analysis of Creep and Shrinkage in Mortars|cements, compressive strength, creep, limes, mortars, shrinkage, stresses|This paper examines the subject of creep and shrinkage in mortars. Previous research has revolved around brickwork or blockwork piers. An experimental program was devised to measure the shrinkage and creep in mortars alone, using a range of seven mortar mixes. Some of the findings confirm earlier research, but considerable additional information concerning creep and shrinkage in mortars has been obtained. Results indicate that the quantity of lime in a mortar is related to shrinkage and creep: the richer the mortar is in lime, the higher the values for creep and the lower the values for shrinkage. The laboratory data add to existing knowledge of mortars and their properties.||Journal Article|666|12624|||8|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903567|83 22|6|1994|556-563|JTE9411|Parker Jr. F, Wu Y|Comparison of Asphalt Contents Measured with the Nuclear Gage and Extraction Methods|asphalt content, hot mix asphalt, nuclear gage, solvent extraction method|Asphalt content is a critical property for controlling the quality of hot mix asphalt. Currently two procedures, solvent extraction (ASTM D 2172, Test Method for Quantitative Extraction of Bitumen from Bituminous Paving Mixtures) and nuclear gage (ASTM D 4125, Test Method for Asphalt Content of Bituminous Mixtures by the Nuclear Method), are used to measure asphalt content. This paper uses field data and data from four laboratory round robin testings to compare asphalt contents measured by the two methods. Asphalt content measurements made by nuclear gages are higher, more accurate, and more precise than asphalt content measurements made by the centrifuge solvent extraction method.||Journal Article|666|12625|||8|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903568|84 22|6|1994|564-570|JTE9411|Todres HA, Bhattacharja S|Solvent-Free, Nuclear-Free Determination of Asphalt Content and Gradation of Hot-Mix Asphalt Concrete|asphalt, asphalt concrete, asphalt content, bitumen, bituminous content, bituminous paving mixtures, gradation, hot mix, nuclear method, pyrolysis, quantitative extraction, sieve analysis, solvent extraction|A new method of analyzing hot-mix asphalt concrete has been developed that involves the pyrolysis or burn-off of the asphalt cement in a furnace. The method is simple and rapid, providing both asphalt content and aggregate gradation within about 1 to 1½ h (substantial reductions in this time appear achievable). The method will permit elimination of solvent and nuclear techniques currently in use that have specific disadvantages and hazards. It can also be used, if desired, to supplement the nuclear gage, in which case burn-off will be used for gradation and the nuclear gage for asphalt content. Methods of performing the test, taking and analyzing data, etc., are described. Results based on aggregates and an asphalt cement widely used in the Chicago area are presented in detail. Further research is under way, and the questions that remain to be answered for the method to be standardized for widespread use are listed.||Journal Article|666|12626|||7|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903569|85 22|6|1994|571-573|JTE9411|Wolfenden A, Gill JE, Chawla KK, Vaidya RU, Venkatesh R|Temperature Dependence of Dynamic Young's Modulus and Mechanical Damping in a Nextel Fiber-Reinforced Glass Composite|ceramics, composites, damping, dynamic, fibers, glass, internal friction, Nextel 480, piezoelectric, temperature, ultrasonic, Young's modulus|The piezoelectric ultrasonic composite oscillator technique (PUCOT) was used to measure the temperature dependence of dynamic Young's modulus and damping for a ceramic matrix composite (CMC) consisting of N51A glass as the matrix and Nextel 480 continuous fibers (volume fraction 0.29) as the reinforcement. The temperature range covered was 20 to 462°C. It was found that the Young's modulus decreased linearly with temperature, at a relatively low rate, and that the damping followed the form exp(-H/kT), where the value of the effective activation energy H was 0.07 ± 0.02 eV/atom, k is Boltzmann's constant, and T is temperature in Kelvin. Possible interpretations for this value of H are discussed. The glass transition temperature of the glass was found to be about 500°C.||Journal Article|666|12627|||3|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903570|86 22|6|1994|577-580|JTE9411|Slaten BL, Shanley LA, Bellingar T|Comparison of Selected Properties of Barrier Textile Materials Used in Durable, Moisture Repellent Protective Clothing|barrier materials, hazardous environments, performance characteristics, protective garments|The needs of workers in hazardous environments are extremely varied. The choice of textile materials must be made on the basis of end use and critical characteristics needed for protection, comfort, and performance of the workers. The purpose of this study was to conduct a series of experiments in order to provide scientific data on the qualities and characteristics of several barrier textile materials. These materials would be suitable for garments for off-shore oil riggers, pesticide applicators, forestry personnel, hazardous waste disposal workers, military personnel, skiers, hikers, and pilots. The following properties were evaluated: stiffness, drape, abrasion resistance, air permeability, water resistance, tear resistance, breaking force and elongation, oil repellency, and soil release. These data provide a range of information on various properties that users of fabrics for protective clothing need to be aware of in the selection of fabrics for garments.||Journal Article|666|12628|||4|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903571|87 22|6|1994|581-583|JTE9411|KarisAllen KJ, Matthews JR|The Determination of Single Edge-Notched Bend Specimen Load Line Displacement from Remotely Located Sensors in Elastic-Plastic Fracture Testing|ASTM E 1152, ASTM E 813, bend bar, fracture, LVDT deflection, machine compliance|ASTM E 813 and E 1152 currently allow for the determination of specimen load point deflection from a remotely located sensor provided that machine compliance (determined from the loading portion of an unnotched bend bar) is removed. If the specimen sustains significant plastic brinelling at the load points, the result is a nonconservative estimate of deflection (and J) subsequent to maximum load. A procedure for the determination of machine compliance relationships for both loading and unloading conditions is presented. Unnotched bend bars of tempered SAE 4340 were tested to compare loading and unloading machine deflection relationships.||Journal Article|666|12629|||3|0|1|1994-11-01 0:00:00||||||||||0090-3973||99903572|88 23|1|1995|3-10|JTE9501|Foulds JR, Woytowitz PJ, Parnell TK, Jewett CW|Fracture Toughness by Small Punch Testing|continuum toughness, disk bend, fracture appearance transition temperature (FATT), fracture toughness, small punch testing, steels|The small punch test, currently being used to empirically estimate the material fracture appearance transition temperature (FATT) of a range of components in fossil power plant service, has been further developed for direct estimation of KIc and JIc in a manner that is analytical, material-independent, and requires no prior knowledge of material mechanical properties. The procedure follows an approach that is based on the continuum material toughness concept wherein the criterion for fracture is defined and measured via the continuum stress-strain deformation properties of the material. The procedure specifically involves computing the "local" strain energy density accumulated at the location and time of crack initiation in the small punch test specimen using large-strain finite element (FE) analysis. Since the procedure also includes estimation of the material uniaxial tensile stress-strain behavior from the small punch load-displacement curve, both the fracture toughness and the uniaxial tensile behavior are determined from a single test. The procedure has been developed in order to take advantage of the miniature sample removal techniques that can be applied "nondestructively" to operating components. Results are presented on a range of steels.||Journal Article|667|12630|||8|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903573|89 23|1|1995|11-18|JTE9501|Shanmugam P, Jana B, Pathak SD|Dynamic Fracture Toughness (DFT) of Banded HSLA Steels|banding, DFT methods, dynamic fracture toughness (DFT) Jld, fracture, high strength low alloy (HSLA) steel, spikes|Dynamic fracture toughness (DFT) evaluation by instrumented impact analysis has been emerging as a time- and material-conservative technique. The present investigation attempts to assess DFT of a high strength low alloy (HSLA) steel showing alternate layers of ferrite and pearlite in microstructure. The banded microstructure has given rise to an irregular stable crack front which shows spikes and splits. Three approaches to evaluate DFT, namely, premaximum energy, compliance changing rate (CCR), and the low blow test method, have been analyzed and compared to assess applicability in the case of irregular crack front. The curve fitting analysis of data justifies the power law fit to give conservative DFT values. The effects of a/w and impact velocity have been investigated. Attempts have also been made to calculate dynamic CTOD from load-displacement curves. Single specimen CCR technique obviates the need for stable crack growth (Da) measurements and predicts conservative DFT values comparable to DFT values obtained from the low blow test method.||Journal Article|667|12631|||8|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903574|90 23|1|1995|19-26|JTE9501|Ragazzo C, Hertzberg RW, Jaccard R|A Method for Generating Fatigue Marker Bands Using a Constant Kmax Test Procedure|constant Kmax fatigue marker bands, contrast differences, micromechanism changes|Marker bands were introduced onto fatigue fracture surfaces by a block loading technique wherein Kmax was held constant while Kmin was varied. Materials examined included Astroloy nickelbase superalloy, 1020 hot-rolled steel. AC 112-TL aluminum, and 2024-T3 aluminum. The use of a constant Kmax test procedure allowed DK to be varied without affecting crack growth rates, thereby providing a convenient method for documenting the shape of a progressing flaw. The nature of contrast differences between marker bands generated at different DK levels were examined in terms of changes in fracture micromechanisms as well as changes in fracture surface roughness. Results indicate that a micromechanism transition from cleavage-like faceted growth at low DK to striated growth at intermediate DK was responsible for the major difference in fracture surface appearance.||Journal Article|667|12632|||8|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903575|91 23|1|1995|27-32|JTE9501|Bolse W, Peteves SD|Indentation Characterization of Silicon Nitride|ceramics, fracture toughness, indentation response, microhardness, silicon nitride|The hardness of hot-pressed silicon nitride ceramics has been measured over a wide range of applied loads, 0.02 to 300 N, for both Vickers and Knoop indenter geometries. The indentation size effect (ISE) was evident for loads less than about 1 N. The Vickers and Knoop hardness values agree provided they are compared at a given penetration of the respective indenter. The influence of the residual stresses of the ceramic surface on the indentation response in the as-machined, polished, and post-annealed state has been investigated. The results are discussed in relation to the characterization of indentation damage in brittle materials and fracture analysis models.||Journal Article|667|12633|||6|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903576|92 23|1|1995|33-40|JTE9501|van Ooij WJ, Sabata A, Zeik DB, Taylor CE, Boerio FJ, Clarson SJ|Metal Surface Preparation by Plasma-Polymerized Films|corrosion, ethylene, hexamethyldisiloxane, plasma polymerization, pretreatments, steel, surface analysis, thin films, zinc|Thin films (<1000 Å thickness) were deposited by polymerization in an RF plasma of hexamethyldisiloxane (HMDS) and ethylene on cold-rolled steel (CRS), electrogalvanized steel (EGS) and on polished pure zinc substrates. Prior to deposition the metals were cleaned in a reactive or nonreactive plasma in the same reactor. The films were characterized by various analytical techniques (FTIR, TOFSIMS, XPS, and AES) for structure, composition, and metal-polymer interfacial composition. All plasma films appeared to be highly polymerized, crosslinked, and virtually insoluble in organic solvents. The ethylene films also showed a high degree of aromaticity and unsaturation. Both types of films afforded excellent resistance of the metal substrate to corrosion in humidity tests at elevated temperatures. The films were stable in air at temperatures up to at least 175°C. Some films provided corrosion resistance even after severe deformation by deep drawing a 5 cm diameter dome in the panel. The corrosion resistance of the film deposited on zinc substrates was usually better than that of the same films on CRS. Analysis by AES indicated that the film-metal interface compositions for these two metals were different. These differences will be related to the surfaces of the substrates.||Journal Article|667|12634|||8|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903577|93 23|1|1995|41-49|JTE9501|Hsu TTC, Belarbi A, Pang X|A Universal Panel Tester|biaxial testing, data acquisition, deformations (strains), hydraulic jacks, loads, membrane element, panel, reinforced concrete, shell element, test facility, triaxial testing, wall|A universal panel tester was built at the University of Houston to test reinforced concrete panel elements subjected to any combination of in-plane and out-of-plane forces. The forces are applied by 40 in-plane hydraulic jacks of 250-kip (1120-kN) capacity each and 20 out-of-plane hydraulic jacks of 140-kip (630-kN) capacity. The sophisticated hydraulic system makes it possible to simulate any complex stress condition in a panel.||Journal Article|667|12635|||9|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903578|94 23|1|1995|50-54|JTE9501|Kain V, Prasad RC, De PK, Gadiyar HS|Assessment of the Corrosion Behavior of SS 304L in Nitric Acid EnvironmentsAn Alternative Approach|austenitic stainless steel, Huey Test (Practice C), intergranular corrosion (IGC), presensitization heat treatment, Rapid Screening Test (Practice A), sensitization|Stainless steel (SS) 304L is widely used as a construction material in industries requiring corrosion resistance in nitric acid environments. Representative samples from 20 heats of SS 304L products were subjected to a testing procedure consisting of testing as per the rapid screening test (Practice A) and the Huey test (Practice C) of ASTM A 262, Practices for Detecting Susceptibility to lntergranular Attack in Austenitic Stainless Steels. The presensitization heat treatment of 677°C for 1 h and the modified heat treatment of 677°C for 20 min were used for characterizing the microstructures in Practice A, whereas only the former presensitization heat treatment was used for Practice C. The percent duality after the two heat treatments has been correlated with the corrosion rate obtained in Practice C. A chemical composition based parameter, Cr effective = [% Cr - 0.18 (%Ni) - 100 (%C)], was calculated for all the heats and correlated with the percent duality after the two heat treatments as well as the corrosion rate in Practice C. It is observed that the SS 304L heats with Cr effective >14.0 and <50% grain boundary coverage after the modified heat treatment (Practice A) show low corrosion rates in Practice C. This eliminates the need for carrying out the lengthy Practice C of ASTM. Examples of heats of SS 304L are given to show that the modified presensitization heat treatment has better efficiency in screening materials and also exhibited better correlation with the results obtained in the Practice C. Guide rules for selection of SS 304L heats for nitric acid service are also suggested.||Journal Article|667|12636|||5|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903579|95 23|1|1995|55-58|JTE9501|Ajayi JO, Elder HM|Effects of Finishing Treatments on Fabric Friction|amplitude, finishing, friction, handle, lubrication, mercerization, roughening, smoothness, softening, stick-slip scouring|Simulation of finishing treatments to knitted and woven cotton fabric substrates causes significant changes in their frictional properties. It is found that the smaller the difference between static and kinetic frictional forces, the smoother the fabric surface. The changes in the amplitude of the stick-slip frictional traces appears to be the best indicator for assessing the effectiveness of finishing treatments on the tactile sensation of smoothness.||Journal Article|667|12637|||4|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903580|96 23|1|1995|59-62|JTE9501|Li JB, Gai XY, Kang ZQ, Wang ZG|Two Parameters Characterizing Superficial Mechanical Features|biaxial stress, effective stress, Mises yielding criterion, surface work hardening exponent, surface yield strength|Two parameters, surface yield strength and surface work hardening exponent, have been newly suggested in this paper to characterize the superficial mechanical features in engineering metallic materials. Emphasis was placed on the method by which the two parameters are determined. X-ray stress determination and strain gage techniques were employed to measure stress and strain. The Mises effective stresses at a sample surface under different loading conditions were then calculated with the measured data; hence, the relationship between stress and strain was available. Consequently, with the data processing procedure for general yield point and work hardening exponent of uniaxially loaded materials, the yield point and work hardening exponent at the sample surface can thereby be obtained. Experimental studies on a shot-peened surface showed satisfactory results when the described method was used.||Journal Article|667|12638|||4|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903581|97 23|1|1995|63-66|JTE9501|Zhu YT, Devletian JH, Chen SJ, Manthiram A|On the Nonuniform Distributions of Temperature and Thermal Stress in DTA Testing|differential thermal analysis (DTA), temperature, thermal strain, thermal stress|A nonuniform distribution of temperature across the solid specimen during differential thermal analysis (DTA) can cause thermal stress. The effect of such thermal stress and the resulting thermal strain energy on the DTA results is theoretically analyzed. It is found that, for most solid metallic specimens, the temperature nonuniformity in the solid specimen is less than 0.18 °C during normal DTA operation. The thermal stress and thermal strain are usually very small due to the small size of the specimen, and they do not have a substantial effect on the DTA results.||Journal Article|667|12639|||4|0|1|1995-01-01 0:00:00||||||||||0090-3973||99903582|98 23|2|1995|73-79|JTE9503|Schmidt PA, Blair RR, Earthman JC|Development of a Novel Specimen Geometry for Fatigue Testing of Fine Wire|cobalt-chromium alloys, corrosion fatigue, Elgiloy, fatigue, fatigue testing, fatigue testing specimen, fine wire, finite element modeling, stress analysis, wire|Despite a critical need to predict component life based on wire fatigue data, a survey of the literature indicates that no standard specimen exists for fatigue testing of fine wires. This article describes a plastically formed, precurved loop specimen developed to meet this need. The loop geometry localizes damage, permitting the use of in-situ, automated crack detection systems. The loop specimen is appropriate for wire diameters between a few hundred micrometres to a few millimetres, and for materials with a high elastic modulus. Material properties are presented for a cobalt-chromium-based alloy (Elgiloy) wire used as a practical example. Analytical and finite element stress analyses are presented which quantify the maximum stress at the loop apex. Fatigue life results using the present specimen are given for Elgiloy wire. Post-test SEM examinations are presented to show that fracture initiation takes place at the maximum stress location as predicted by the analyses. A fracture path and morphology characterization is also shown to be consistent with the anticipated stress regimes.||Journal Article|668|12640|||7|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903583|99 23|2|1995|80-86|JTE9503|Yang L, Fatemi A|Deformation and Fatigue Behavior of Vanadium-Based Microalloyed Forging Steel in the As-Forged and Q&T Conditions|cyclic creep, cyclic loading, cyclic plastic deformation, cyclic relaxation, cyclic transient behavior, deformation, fatigue life, low cycle fatigue, microalloyed (MA) steel, monotonic loading|The use of microalloyed (MA) forging steels in the asforged condition can result in the elimination of the costly post-forging quenching and tempering (Q&T) processes. MA steels can therefore serve as economical alternatives to the traditional Q&T steels if equivalent mechanical properties can be obtained. In this study, monotonic and cyclic behaviors of a vanadium-based MA forging steel, one of the most commonly produced MA steels, were investigated under both the as-forged and Q&T conditions. The mechanical properties evaluated and compared include monotonic tensile behavior, cyclic deformation response, and low and high cycle fatigue resistance. Experimental results are presented and the differences in the behaviors under the two processing conditions are discussed.||Journal Article|668|12641|||7|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903584|100 23|2|1995|87-94|JTE9503|Sengupta A, Putatunda SK|Dynamic Strain Aging in a New Single Crystal Nickel-Based Superalloy (CMSX-4)|dislocations, dynamic strain aging, elevated temperature, nickel-based superalloy, pinning, single crystal, solute atoms, tensile properties, true strain rate|Tensile behavior of a new single crystal nickel-based superalloy with rhenium (CMSX-4) was studied at both room and elevated temperatures in two different heat-treated conditions. Detailed fractographic studies were carried out to determine the micromechanism of crack growth in tensile loading. Round cylindrical tension specimens were prepared from the single crystal nickel-based superalloy CMSX-4 in [001] orientation. The test specimens had the [001] growth direction parallel to the loading axis in tension. The specimens were given two different heat treatments to produce two different g¢ precipitate sizes, i.e., 0.3 mm and 0.5 mm, respectively. The tensile properties of these materials were evaluated at room and elevated temperatures in ambient atmosphere as per ASTM E 21, Test Methods for Elevated Temperature Tension Tests of Metallic Materials. The results of this investigation indicate that CMSX-4 undergoes dynamic strain aging in the temperature range of 260° to 875°C. This dynamic strain aging appears to take place by the trapping of moving dislocations by the substitutional solute atoms (like rhenium, tantalum, tungsten, cobalt, and molybdenum) during the high-temperature deformation process. Fractographs at lower temperatures (T £ 800°C) exhibit an unusual type of cleavage fracture with several operative slip systems, while at higher temperatures (T ³ 1094°C) the crack growth process is characterized by a relatively smooth fracture surface, with the presence of dimples created by ductile failure (typical of many nickel-based superalloys).||Journal Article|668|12642|||8|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903585|101 23|2|1995|95-101|JTE9503|McNaney JM, Cannon RM, Ritchie RO|Elastic Compliance of Four-Point Bend Specimens Comprising Two Linear-Elastic Materials Bonded with a Thin Layer|back-face strain (BFS), bimaterial "sandwich" specimen, compliance methods, crack-length monitoring, crack-opening displacement (COD), load-line displacement (LLD)|The four-point bend "sandwich" specimen, comprising two identical linear-elastic substrates joined by a thin elastic layer, is widely used in the study of strength and toughness of bimaterial joints loaded under nominal mode I loading. As an aid to crack monitoring in such specimen geometries, the linear-elastic compliance based on load-line displacement, back-face strain, and crack-opening displacement has been determined for a wide range of substrate/layer material combinations using finite-element analyses. Calculations for bimaterial systems, with elastic moduli ratios varying from 0.2 to 5 and with joining layer thicknesses between 100 and 500 mm, show that for crack sizes between 0.1 to 0.7 of the specimen width, the compliance is significantly different from that of the bulk substrates, even when the layer is very thin. It is concluded that crack-opening displacements are preferable for the monitoring and detection of interfacial and near-interfacial cracks in this specimen geometry, as the compliance based on these displacements is the least sensitive to errors from either measurement site or crack location.||Journal Article|668|12643|||7|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903586|102 23|2|1995|102-110|JTE9503|McKeighan PC, Zhu W-X, Smith DJ|A Full Field DC Potential Drop Calibration for an Asymmetrically Cracked M(T) Specimen|analog technique, calibration errors, crack asymmetry, crack length errors, potential drop (PD)|A direct current (DC) potential drop (PD) calibration tool, in the form of a computer program, is provided that can determine the PD response at any point in an M(T) specimen containing either a symmetric or asymmetric crack. Results from the program were verified using data in the literature and results from an analog simulation. If a standard PD calibration is applied to the PD response for an asymmetric crack, the total crack length will be underestimated which leads to significant stress intensity factor errors for even small amounts of asymmetry. Using the PD response of an asymmetric crack from an analog simulation, three methods to predict individual crack lengths are evaluated. The methods use a two-dimensional (2-D) iterative procedure to solve for crack length given voltages from at least two sets of probes located at different positions on the specimen. Any of the different methods, which use different probe locations as the calibration inputs, yield good crack length predictions for crack length to specimen width ratios a/W greater than 0.25. However, the most numerically robust method resulting in the least error over a large crack length range uses the PD from a centerline probe and the PD difference from two offset probes to predict the crack length. These predictions result in a crack length error that does not exceed ±0.004 W and consequently result in insignificant stress intensity factor errors.||Journal Article|668|12644|||9|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903587|103 23|2|1995|111-118|JTE9503|Burnett AD|A Quantitative X-Ray Diffraction Technique for Analyzing Sedimentary Rocks and Soils|analysis, clay, clay fraction, mineralogy, quantitative analysis, sedimentary rocks, sediments, soil, whole rock, X-ray diffraction|Mineralogical studies of sedimentary rocks or sedimentary deposits are often required for engineering geological projects. X-ray diffraction analytical techniques are usually employed for this purpose but these methods are often complex and involved. Several different X-ray diffraction methods are described and a single suitable procedure is chosen and described in detail. The chosen method includes analysis of both clay and non-clay minerals and qualitative and quantitative interpretation.||Journal Article|668|12645|||8|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903588|104 23|2|1995|119-125|JTE9503|Sabata A, Knueppel BA, van Ooij WJ|TOFSIMS Studies of Cleaning Procedures and Silane Surface Treatments of Steels|adhesion, adhesive, cleaning, steel, surface analysis, zinc|Surface contaminants can affect properties such as wettability and reactivity in subsequent surface preparation processes. Cleaning of metal substrates has usually been studied by techniques such as AES and XPS. These techniques do not give any information on the molecular structure of the contaminants; however, Time-of-Flight Secondary Ion Mass Spectrometry (TOFSIMS) with its monolayer sensitivity, has been effective in providing structural, molecular information of organic contaminants which may be useful in identifying the source of the contamination. Industrial alkaline cleaning and degreasing processes leave mainly a siloxane-type of contaminant that deteriorates the adhesion of metals to epoxies. Phosphating leaves the surface clean and microrough, which improves the adhesion of adhesives to cold-rolled steel (CRS). Epoxies when cured at high temperatures give better adhesion values as compared to room temperature epoxies. Organofunctional silanes such as styrylamino aminopropyltrimethoxysilane (SAAPS) were found to have a specific orientation on the metal substrate as a function of cleanliness and mode of application. The orientation of the vinylbenzyl group towards the epoxy adhesive is shown to improve adhesion. A combined silicate and silane post-rinse of phosphate coatings is shown to be effective in giving the silanes the required orientation for bonding to epoxies, thus improving the adhesion.||Journal Article|668|12646|||7|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903589|105 23|2|1995|126-129|JTE9503|Mu X, Ma X, Zhuang Y|A Study of the Fatigue Softening and Hardening of Steel by the Magnetoelastic Effect Method|fatigue, hardening, magnetic anisotropy, magnetoelastic effect, softening|With a specially designed sensor and testing system, a study was made on the changing pattern of the magnetic induction sensitivity signal induced by magnetic anisotropy during the fatigue processing of carbon steel. It was found that signal change has several characteristic stages and obvious extreme points. The points coincided with the position of the fatigue strain peaks. The signal change was related to fatigue softening and hardening, and synchronous with the change in the surface residual stress.||Journal Article|668|12647|||4|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903590|106 23|2|1995|130-135|JTE9503|Mirizzi SA, Baseheart M, Rieser LA, Kramer TE|Monitoring of Cement Stabilized Surrogate Waste Using Resonant Frequency Techniques|acoustic methods, cement stabilization/solidification (CSS), durability testing, frequency response function (FRF), nondestructive testing, resonant frequency testing|It is often necessary to track incremental changes in the physical properties of composites with portland cement binders caused by chemical attack, freeze-thaw cycles, and other deterioration mechanisms. The vibration testing procedure presented for measuring the resonant frequency of a specimen is directly applicable to the monitoring of the deterioration of stabilized/solidified waste specimens. The change in the fundamental frequency is significantly more sensitive than the loss of mass to the internal changes in the mechanical properties of specimens. The time and effort required to determine the fundamental frequency of a specimen is also significantly less than that required to determine the loss of mass of the same specimen. The proposed method has been demonstrated to work on small cylindrical specimens (44 mm by 74 mm) with aspect ratios less than 2.0. The use of elastomeric bands as the means of attachment of the specimen to the test equipment does not interfere with or limit other chemical and mechanical performance tests scheduled for the specimens.||Journal Article|668|12648|||6|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903591|107 23|2|1995|141-144|JTE9503|Li D-B, Chui YH, Smith I|A Vibration-Based Method for Determining St. Venant Torsional and Warping Stiffnesses of Members with Open Cross-Sections|mechanical property identification, St. Venant torsional stiffness, warping stiffness|A dynamic mechanical property identification method is presented based on a study of composite wood members with an open I-shape cross-section. Besides the bending stiffness which is identified by a bending vibration test, St. Venant torsional stiffness GKs and warping stiffness EKw are identified by a separate torsional modal analysis. Three kinds of typical I-shape beams have been tested and their properties identified. The approach is based on Euler beam theory and an earlier torsional vibration model developed by the authors.||Journal Article|668|12649|||4|0|1|1995-03-01 0:00:00||||||||||0090-3973||99903592|108 23|3|1995|153-159|JTE9505|Makabe C, Kaneshiro H, Nishida S, Sakihama H|A Consideration of Evaluation of Fatigue Crack Propagation Rate from Effective Stress Intensity Factor Range|crack closure, effective stress intensity factor range, fatigue crack propagation, overload, welding residual stress|The fatigue crack propagation law was investigated for the two cases of crack propagation in a region of welding residual stress and after overloading. In the former case, the crack propagation rate da/dN was found to depend on the stress ratio R defined by smin/smax where smin, smax are the minimum and maximum cyclic stresses. Due to the tensile residual stress, the crack propagation rate increased as the stress ratio decreased in the range -2 £ R £ 0. In the latter case, the crack propagation rate da/dN after overloading was higher than that for the constant stress amplitude test at first and then became lower. The crack propagation rate was thus affected by both the residual stress and the overloading. However, the crack propagation behavior correlated well with the crack closure behavior. Therefore, in the cases considered here, the crack propagation law can be reasonably evaluated from the effective stress intensity factor range DKeff.||Journal Article|669|12650|||7|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903593|109 23|3|1995|160-167|JTE9505|Merah N, Bui-Quoc T, Bernard M|Calibration of DC Potential Technique Using an Optical Image Processing System in LCF Testing|crack growth, DC potential technique, high-temperature testing, low-cycle fatigue, video-camera crack monitoring|The direct current electrical potential drop (DCPD) technique is applied to monitor fatigue crack growth in plate specimens with central circular holes at room and high temperatures. The application of the calibration curves obtained from replica specimens to both room and high-temperature fatigue testing conditions is studied. The actual fatigue crack length is measured using a video-camera with image processing to assess the reliability of the DCPD technique. The use of two pairs of DCPD probes across the hole and the introduction of a special reference voltage have eliminated the dependence of the potential drop on the hole size and shape as well as the material resistivity and the notch plastic zone size prior to crack initiation. At high temperature, however, the calibration curve should be corrected to take into account the shifting in the potential ratio due to the increases in crack tip plastic zone and crack opening displacement. The effect of the temperature difference between the different potential probes is also examined. By analyzing the results given by the DCPD in connection with the image processing technique, a criterion is suggested to define the interface between the crack initiation and propagation periods.||Journal Article|669|12651|||8|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903594|110 23|3|1995|168-175|JTE9505|Lee HM, Moon H, Pyun S-I|Relationships between Specimen Size, Stress Rate, and Load-Controlled Tensile Properties of AISI 300 Series Stainless Steels at 4 K|4 K, cryogenic temperature, discontinuous yielding, liquid helium, load control, load rate, specimen size, tension test|The effects of specimen size on the load-controlled tensile properties of AISI 304, 316, and 310S stainless steels at 4 K were examined at four different stress rates from 0.154 to 154 MPa/s. Diameters of the specimens were 4.5, 6.35, and 8 mm. The stress and strain at the onset of the discontinuous yielding on the ultimate tensile strength are discussed. The differences in the effect of the machine control mode on the mechanical properties are also discussed.||Journal Article|669|12652|||8|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903595|111 23|3|1995|176-179|JTE9505|Wolfenden A, Schwanz WR|An Evaluation of Three Methods to Measure the Dynamic Elastic Modulus of Steel|1018 steel, density, dynamic impulse excitation, elastic modulus, flexural modulus, magnetic, piezoelectric, ultrasonic, Young's modulus|The dynamic elastic modulus of 1018 steel was measured with three different instruments: the Grindo-Sonic, the Modul-R, and the piezoelectric ultrasonic composite oscillator technique (PUCOT). In total, 276 tests were made. The overall mean elastic modulus for all the specimens and all three methods was 207.1 GPa with a standard deviation of 2.75 GPa (1.33%). The mean values of elastic modulus and standard deviation measured by the Grindo-Sonic, the Modul-R, and the PUCOT were 208.1 and 0.86 GPa (0.41%), 205.8 and 3.40 GPa (1.65%), and 207.9 and 2.80 GPa (1.35%), respectively. The means of the elastic modulus for the PUCOT, Grindo-Sonic, and Modul-R methods fell within 0.39%, 0.48%, and 0.63%, respectively, of the overall mean elastic modulus of 207.1 GPa. All three instruments yielded comparable values of elastic modulus and comparable standard deviations. However, the Grindo-Sonic and Modul-R instruments were quicker for use than the PUCOT, but the PUCOT was more forgiving on the specimen geometry than the other two instruments.||Journal Article|669|12653|||4|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903596|112 23|3|1995|180-188|JTE9505|Chen D-H, Zaman MM, Laguros JG|Characterization of Base/Subbase Materials under Repetitive Loading|aggregate, base and subbase materials, granular materials, repetitive loading, resilient modulus|Testing of granular materials for evaluation of Resilient Modulus (MR) suffers from the lack of a standardized test method. Although AASHTO over the past six years (1986 to 1992) has proposed three different testing procedures (T274-86, T292-91I, and T294-92I), some state transportation departments have adopted their own MR testing procedures. In this study, the factors affecting the measurement of MR such as the testing method used and stress applied and its sequence are investigated. In addition, the updated methodologies proposed by various agencies for MR of granular materials and the MR values obtained are reviewed and evaluated. It is found that the applied stress sequence has some effects on MR of granular materials. For the two aggregate types investigated in this study, with the same location of LVDT and dynamic waveform, the T294-92I testing procedure yields higher MR than that obtained by using the T292-91I testing procedure. The stress sequence in T294-92I infers a stiffening and strengthening effect on the specimen structure as the stress level increases from low to high. The variation of MR values due to testing procedure is found to be higher than those due to the aggregate source. The MR values obtained in this study are found to be lower than those reported in the literature. Furthermore, with the updated testing procedure for MR, the correlation between the structural layer coefficients and MR of granular base and subbase proposed by the AASHTO needs to be modified accordingly.||Journal Article|669|12654|||9|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903597|113 23|3|1995|189-195|JTE9505|Sebaaly PE, Tabatabaee N, Kulakowski B|Evaluation of the Hall Effect Sensor for Pavement Instrumentation|asphalt concrete, flexible pavement, Hall Effect sensor, H-gage, modulus, moisture, regression, repeatability, strain gage, survivability, temperature, tensile strain, uncertainty|This research evaluates a new concept to measure the tensile strains at the bottom of the asphalt concrete layer in flexible pavements. The concept consists of using the Hall Effect sensor in an H-gage configuration to measure the dynamic strains in flexible pavements. The evaluation program included both laboratory and field experiments to evaluate the fundamental and operational properties of the recommended gage design. The laboratory experiment showed that the Hall Effect gage can withstand the temperature and moisture conditions that are encountered during the construction and operation stages of hot mixed asphalt concrete pavements. It also indicated that the dynamic characteristics of the gage are suitable for measuring pavement strains under moving vehicle loads. The field experiment evaluated the in-service characteristics of the Hall Effect gage under a large number of combinations of vehicle speed, axle load, and tire pressure. The field data showed that the Hall Effect gage has good survivability and repeatability and it compares favorably with other strain gages that have been used in flexible pavements.||Journal Article|669|12655|||7|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903598|114 23|3|1995|196-202|JTE9505|Ochi SCU, Accorsi ML, Jordan EH|Influence of Embedded Markers on the Response of the Host Material|embedded markers, host material, smart materials|The effect of embedded marker particles on global stiffness and strains determined when using these markers as fiducial marks is studied analytically. These effects are important to a recently developed strain measurement method that uses before and after X-ray pictures of the embedded marker particles. Global effect of the markers on the stiffness is studied using micromechanical models available from the literature. The error in the measured strain due to the influence of the markers is assessed by both the finite element method and elasticity theory. It is shown that the global influence is small for marker-volume fractions less than 3%. The induced strain measurement error is small for particles that are five or more marker-diameters apart. A simple formula for the strain measurement error in the case of particles that are five or more marker-diameters apart is derived from elasticity theory.||Journal Article|669|12656|||7|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903599|115 23|3|1995|203-208|JTE9505|Porzucek K, Lefebvre JM|Relationships between Tensile Stress Relaxation Behavior and Short-Term Elastic Recovery for Linear Low-Density Polyethylenes|elastic recovery, stress relaxation, Tensile Residual Deformation (TRD)|Tensile stress relaxation is shown to be an experimental way to quantify the short-term elastic recovery of linear low-density polyethylenes (LLDPEs). The evolution of the force decrement DF with the logarithm of time is described by two linear equations on both sides of a critical time value tc = 100 s. The slope p1 of the DF - ln(t) plot below tc increases linearly with the percentage of elongation e up to the critical ec value associated with the onset of the yielding plateau; beyond ec, p1 remains almost constant with e. This constant p1p value is a linear function of the Tensile Residual Deformation (TRD) measured at the end of the relaxation: the lower the p1p value, the lower the TRD. The determination of p1p thus appears as a predictive tool of the short-term elastic recovery of a material. Results show that the p1p slope is slightly more sensitive to density evolutions than the TRD value. Assessing the elastic recovery capability through a stress relaxation analysis offers the following advantages: operator-independence, time-saving, and possibility of information storage for further data treatment.||Journal Article|669|12657|||6|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903600|116 23|3|1995|209-216|JTE9505|Pastor JY, Planas J, Elices M|A New Technique for Fracture Characterization of Ceramics at Room and at High Temperature|ceramic materials, crack mouth opening displacement (CMOD), high temperature, high-resolution extensometry, specific fracture energy, stable fracture tests|A new technique for performing stable tests in ceramic materials is analyzed in depth. The new feature consists in using an analog output of a laser metrology apparatus that measured the crack mouth opening displacement (CMOD), as the feedback signal to control a servohydraulic testing machine. In this study, we go deeply into the analysis of the experimental parameters that control the performance of this technique. Finally, the temperature dependence is shown for the fracture parameters obtained from stable tests of single-edge-pre-cracked-beam specimens (SEPB) of 3 mol% Y-TZP.||Journal Article|669|12658|||8|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903601|117 23|3|1995|217-221|JTE9505|Sundaram SK, Speyer RF|Evaluation of the Corrosion of MoSi2 by Molten Glass|ASTM C 621 method, glass corrosion testing, modifications, molybdenum disilicide (MoSi2)|Modification of ASTM C 621 is needed in order to determine the corrosion of the material MoSi2 by molten glass since this material reacts with the prescribed platinum crucible. The latter was replaced with a fusion-cast alumina-zirconia-silica refractory crucible. A correction for the width of the saw kerf is suggested. The modified method was carried out on a number of cylindrical samples in molten E-glass at 1550°C. The specimen-glass interfacial regions were characterized using SEM, EDS, and XRD.||Journal Article|669|12659|||5|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903602|118 23|3|1995|222-227|JTE9505|Sivapullaiah PV, Prashanth JP, Sridharan A|Optimization of Lime Content for Fly Ash|calcium silicate hydrate, fly ash, free swell index, liquid limit, optimization, pH, pozzolanic reactivity, unconfined compressive strength|Abundant quantities of fly ash have been produced by thermal power plants situated all over the world. Many applications of fly ash depend upon its pozzolanic reactivity. This reactivity depends upon many factors, including lime content. Many fly ashes show marked improvement with the addition of lime. However, for every fly ash, there is an optimum lime content for its maximum reactivity. There is no well-established simple test to determine the optimum lime content. In this paper an attempt is made to use a simple physical and physico chemical test to determine the optimum lime content. The principle behind the use of a pH test, liquid limit test, and free swell index test to determine the optimum lime content has been explained. All the methods predict nearly the same optimum lime content and correlate well with that determined by the strength test.||Journal Article|669|12660|||6|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903603|119 23|3|1995|228-230|JTE9505|Prakash V, Chen CM, Engelhard A, Powell G|Torsional Fatigue Test for Adhesive Bonded Butt Joints|adhesive joints, butt joint, fatigue, torsion|A torsional fatigue test for adhesive bonded butt joints is presented. The apparatus for the test is a modification of the standard fixture outlined in the ASTM E 229 test for determining the shear strength of adhesive bonds subject to torsion. This apparatus is designed to be used on a universal testing machine and can be used to determine the fatigue life of adhesive butt joints under torsion. The fixture can be further modified to make it suitable for testing adhesive bonded shaft joints under torsion. Sample results from fatigue tests performed on a joint between steel and phenolic resin-cotton fiber laminate adherends are presented to show the viability of the fatigue test apparatus.||Journal Article|669|12661|||3|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903604|120 23|3|1995|231-234|JTE9505|Bhuyan GS|Crack Initiation Fracture Toughness of Transmission Line Hardware Steels|AC potential drop, initiation fracture toughness, transmission hardware steels|Initiation fracture toughness of some selected steels used for transmission line hardware components was measured using an AC potential drop method. The moderate upsetting due to the forging operation of the 1541 bar material increased the initiation fracture toughness by up to 27%, as compared to that of the rolled bar. Initiation fracture toughness of the oil-quenched 4140 steel increased by 60% with the decrease in hardness from Rc 40 to 28.||Journal Article|669|12662|||4|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903605|121 23|3|1995|235-237|JTE9505|Bhuyan GS|Effect of Cold-Bending and Strain-Age-Embrittlement on the Fracture Behavior of CSA G40.21 M 350 WT Steel|Charpy energy, cold-bending, CSA 350 WT steel, galvanizing, strain-age-embrittlement, transition temperature|The galvanizing process shifted the scatter band for impact energy values of the CSA 350 WT, category 4, plate material by approximately 10°C. The cold-straining alone produced the most significant shift (30°C) in the ductile-to-brittle transition temperature. This particular steel was found to be less susceptible to strain-age-embrittlement.||Journal Article|669|12663|||3|0|1|1995-05-01 0:00:00||||||||||0090-3973||99903606|122 23|4|1995|241-253|JTE9507|Moidu AK, Sinclair AN, Spelt JK|Analysis of the Peel Test: Prediction of Adherend Plastic Dissipation and Extraction of Fracture Energy in Metal-to-Metal Adhesive Joints|elastic foundation, elastic-plastic beam, energy balance, fracture energy, metal-to-metal adhesive joints, mode ratio, peel test, plastic dissipation|The peel test has been widely used for the mechanical measurement of the adhesion phenomenon. However the proportion of the energy input dissipated plastically within the adherend is a major concern in analyzing peel test data. This paper presents an analytical approach to predict the adherend plastic dissipation in the peel test for metal-to-metal adhesive joints, thereby allowing the fracture energy to be extracted from the test data using an energy balance approach. Expressions are developed for the deflection of an elastic-plastic beam on an elastic foundation, which is then combined with known solutions for the deformation of an elastic-plastic strip under large displacement. The model takes into account both the adhesive and adherend compliance effects on the plastic dissipation. Numerical predictions of the model are presented to gain insight into the effects of adherend properties and peel angle on plastic dissipation in the peel test. It is demonstrated that experimental results with various adherend properties and peel angles are consistent with the predictions of the model. An important conclusion is that for typical structural adhesives, the effects of plastic dissipation may be kept small by using a relatively low yield strength alloy with a thickness much smaller than the critical thickness at which the plastic dissipation effect is a maximum. The extraction of the fracture energy from the test data is also discussed with regard to the mixed-mode nature of the peel test.||Journal Article|670|12664|||13|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903607|123 23|4|1995|254-260|JTE9507|Yee R, Lambert SB|A Reversing Direct Current Potential Drop System for Detecting and Sizing Fatigue Cracks along Weld Toes|boundary element analyses, fatigue cracks, foil analogue method, reversing direct current potential drop method (DCPD), weld toes, welded steel T-joints|Steel welded T-joints with 102 mm thick base plates were fatigue tested in three-point bending. A reversing direct current potential drop (DCPD) system was used to detect the initiation of multiple surface cracks along the transverse weld toes of these joints and to monitor the size and shape of fatigue cracks that developed from these cracks. Potential drop readings were obtained by fixed probes straddling the weld toes and normalized with respect to potential drop readings from a remote reference probe. The normalized potential drop readings from each probe were related to the local crack depth by two-dimensional (2-D) calibrations derived by boundary element analyses and the foil analogue method. The fixed-probe arrangement was able to detect 0.4 mm to 1.0 mm deep surface cracks along the transverse weld toes of the T-joints. The 2-D calibrations were able to predict the crack depth at the deepest points of these cracks to within ± 10%.||Journal Article|670|12665|||7|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903608|124 23|4|1995|261-266|JTE9507|Vandeput FR|Strength Testing of Brittle Materials in Tubular Form Using Elastomeric Inserts|brittle materials, burst testing, fracture, tungsten carbide|The tensile strength of a brittle material can be determined by bursting of tubular test specimens. A bursting test in which a tube is partially pressurized by an elastomeric insert is described. The results of the bursting test can be correlated with the transverse rupture strength of the material by using statistical fracture theories that take into account the size, stress distribution, and stress state in the test specimens. Bursting and three-point bending tests were conducted on cemented tungsten carbide specimens. The transverse rupture strength obtained from the three-point bending tests was correlated with the hoop strength of the tubes using the Barnett-Freudenthal and Weibull theory of fracture.||Journal Article|670|12666|||6|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903609|125 23|4|1995|267-274|JTE9507|Marur PR, Simha KRY, Nair PS|A Compact Testing System for Dynamic Fracture Studies|crack propagation velocity, dynamic fracture toughness, instrumented impact tests, three-point bend specimens|Development of a compact instrumented impacting apparatus for dynamic fracture studies designed on the lines of a swing pendulum machine is described. Salient features of the system and instrumentation calibration procedures are presented. The dynamic characteristics of the system are explained with the aide of a simple inertial model. Results of dynamic fracture experiments conducted on aluminum 6061 alloy and polymethylmethacrylate (PMMA) are discussed.||Journal Article|670|12667|||8|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903610|126 23|4|1995|275-280|JTE9507|Ruiz J, Elices M|Ultra-High-Vacuum Chamber for Environmental-Fatigue Testing|crack growth rate, environmental crack growth, fatigue, high vacuum, water vapor|This paper describes an ultra-high-vacuum (UHV) chamber for environmental fatigue crack growth tests. The main components of this testing device are the working chamber, where the test is conducted, the gas entry lines, and the quadrupole chamber, which is used for analyzing the environment. Advice on the assembly and behavior of these components is also given. As an example of the performance of the system, novel results are reported of crack growth rates in an aluminum alloy (AA7017-T651) when tested in high vacuum, pure oxygen, and at different water vapor pressures.||Journal Article|670|12668|||6|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903611|127 23|4|1995|281-287|JTE9507|Narendranath CS, Srinivasan MN|Effect of Cooling Rate Variables on the Solidification Time and Microstructure of Permanent Mold Magnesium-Treated Iron Castings|cast iron, graphite, heat conduction, microstructure, permanent mold, solidification, thermal convection|This paper deals with studies on the effect of cooling rate variations on the solidification times and microstructure of permanent mold magnesium-treated cast iron. Cooling rate variations were brought about by changes in the casting size or mold preheating temperature or mold wall thickness. The results of this investigation indicate that the solidification time of magnesium-treated iron casting is always greater than that of an untreated iron casting, when the cooling rate variables are similar. Since the morphology of graphite in the two cases is different, it is thus indicated that graphite morphology affects the solidification time. Though the solidification time of magnesium-treated iron permanent mold castings shows an increase when the casting size is increased, no unilateral increase or decrease is observed when the magnitudes of the other two variables, viz., mold wall thickness and mold preheating temperature favor decrease and increase in cooling rate respectively. Microstructural analysis indicated that random variations in the graphite morphology, despite the residual magnesium being above the required limit, were primarily responsible for the random variations in solidification times. The reason for this randomness has been discussed in terms of heat transfer. Further experiments were conducted where the heat transfer variables were chosen based on this analysis and it was possible to achieve proper trends in the solidification time. The graphite shape of the castings in these experiments had good nodularity, with the size being related to the cooling rate.||Journal Article|670|12669|||7|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903612|128 23|4|1995|288-294|JTE9507|Eliasson J, Sandström R|Analysis of the Coherence of Published Data on Aluminum Matrix Composites|aluminum, composite, database, meta data|Data on aluminum matrix composites were previously collected from scientific articles and analyzed. The purpose was to make it possible to select composite materials. During data analysis, incomplete representation of the information was discovered in many cases. Since this situation is not uncommon for advanced materials, it was decided to characterize the information that was missing. Important information has been divided into three main groups: mandatory, essential, and recommended meta data, where the meta data is the background information to actual data. Missing mandatory meta data make it impossible to verify the results by repeating the testing, e.g., when the composition of the matrix, the type and amount of reinforcement or the heat treatment is missing. The percentage of the 93 studied articles with such data missing was about 20%. If there is essential meta data missing, the precision in the interpretation of property data is significantly limited. Examples of essential information are processing steps, reinforcement length, and size. In about 60% of the articles some essential meta data were missing. Recommended meta data are, for example, description of the microstructure or other background information such as reinforcement distribution. The fraction of articles missing some recommended meta data is almost 100%. The lack of data leads to difficulties interpreting and modeling experimental data which will ultimately slow large-scale introduction of aluminum matrix composites.||Journal Article|670|12670|||7|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903613|129 23|4|1995|295-299|JTE9507|Mackes KH, Loferski JR, White MS|A Pneumatic Pressure Bag Testing Machine for Applying a Uniform Load to Panels and Pallets|finite element program, pneumatic pressure bag testing machine, steel plate, uniformly distributed load|Methods for applying uniformly distributed loads to structures are evaluated. A detailed description is presented for a pneumatic pressure bag (airbag) testing machine built by researchers at Virginia Polytechnic Institute and State University. A 48 in. (1.219 m) square steel plate with an average thickness of 0.498 in. (0.01265 m) was tested to determine whether the machine delivers a true uniformly distributed load. Experimental results are compared to an analytical solution obtained using the ABAQUS finite element program. Results show that the deflection pattern of the plate along its length at midspan is parabolic, with deflections being greatest at the free edges and least at the plate center. Errors range from 0.6% at one free edge to 3.8% at the other. The error at the plate center is 1.4%. The close agreement between finite element and experimental values indicates that the load applied by the airbag testing machine is a good approximation of a truly uniform load.||Journal Article|670|12671|||5|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903614|130 23|4|1995|300-306|JTE9507|Xu Y, Zhao Z|A Modified Miniature Disk Test for Determining Material Mechanical Properties|conversion data, ductility, elastic-plastic bulge deformation, middle-thick circular plate, modified miniature specimen test (MMST), strength|This paper briefly describes the apparatus and experimental procedure for the modified miniature specimen test (MMST). The primary focus is on the thought and methodology of converting data. The accuracy and reliability of test results are emphasized. The fundamental relations for converting experimental data are established via analysis of elastic-plastic bulge deformation behavior of a middle-thick circular plate loaded at the center for which the circumference is fixed and points at the boundary can move in a radial direction. The formulas for calculating materials strength and ductility have been derived from the relation. Three types of unirradiated materials whose strengths are different and one kind of 316 SS irradiated by protons were tested with MMST. The test results along with the standard deviations are presented. The comparison of these data with that for uniaxial tension tests is also given. The evaluation of material equivalent fracture strain was also performed with the MMST.||Journal Article|670|12672|||7|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903615|131 23|4|1995|307-310|JTE9507|Whelan AE|Characterizing Shock Absorbers for Ground Vehicle Simulation|characterization, force response surface, ground vehicle simulation, modeling, shock absorber|A new method of ground vehicle shock absorber characterization using lumped acceleration excitation is presented. By using a triangular waveform and lumping the acceleration at the beginning and end of travel, this method produces a 27% larger mapping on the phase plane than traditional harmonic (sinusoidal waveform) excitation characterization. Force response surfaces are created based on the lumped acceleration and on harmonic excitation data. A difference surface is created between the common regions of both force response surfaces. A correlation is made between the response of the lumped acceleration force response surface to harmonic inputs and observed data. Hysteresis effects are noted using the lumped acceleration force response surface at low frequencies. A standard materials testing machine is used to characterize the shock absorber.||Journal Article|670|12673|||4|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903616|132 23|4|1995|311-314|JTE9507|Kim J-D|Effect of Carbide and Oxide Coating Thickness on Cutting Tool Wear in the Turning Process|carbide, coating thickness, oxide coating, TiC coating, tool wear|In this investigation, tool grade P20 WC was coated using the Chemical Vapor Deposition (CVD) method. The specimen was coated uniformly with A12O3 of 1.5 mm thickness over an additional coating of TiC. TiC coating thickness varied at four different thicknesses: 3 mm, 6 mm, 9 mm, and 12 mm. The investigation was conducted with a turning operation in high-strength steel at higher cutting speed. Using SEM and X-ray, the progress of crater wear was carefully observed.||Journal Article|670|12674|||4|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903617|133 23|4|1995|315-318|JTE9507|Lawson L, Chen EY|Microcracks: The Hazard Function and Reliability Inspection|crack density, hazard function, initiation, microcracks, reliability inspection|Reliability inspections of structures for fatigue cracks are traditionally conducted at equispaced intervals because, it is assumed, the average slope of the hazard function following an inspection does not change from one inspection to the next. This study examines the common case where fatigue cracks nucleate continually over time. In such cases it is found that the slope of the hazard function after inspection may tend to increase from one inspection to the next, suggesting that inspection intervals should decrease with increasing service life. A formalism is introduced that allows calculation of the hazard function from microcrack data.||Journal Article|670|12675|||4|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903618|134 23|4|1995|319-321|JTE9507|Tew BW, Blackketter DM, Lemmon RK|Stiffening Effects of Photoelastic Coatings on Orthotropic Plates|experimental methods, orthotropic materials, photoelasticity, stress analysis|Photoelastic coatings have been used successfully for years to help engineers understand the stress state within a test specimen or structural component under load. For very stiff specimens, the addition of a photoelastic coating does little to change the stress state within the specimens. However, photoelastic coatings used with relatively flexible specimens have a significant stiffening effect which has been quantified and documented for isotropic materials. Correction factors have been developed that allow the analyst to account for the stiffness added to the specimen by the coating. This technical note addresses the stiffening effect of isotropic photoelastic coatings on orthotropic specimens, and provides orthotropic correction factors needed to correctly interpret stress results obtained using photoelastic analyses. The derivation of these correction factors assumes that loads are applied only along principal planes. Consequently, shear stresses due to specimen orthotropy are not present.||Journal Article|670|12676|||3|0|1|1995-07-01 0:00:00||||||||||0090-3973||99903619|135 23|5|1995|325-332|JTE9509|Putatunda S, Singh I|Fracture Toughness of Unalloyed Austempered Ductile Cast Iron (ADI)|alloying elements, austempered ductile cast iron (ADI), austempering, austenite, cast iron, ferrite, fracture toughness, mechanical properties|The influence of microstructure on the tensile properties and the plane strain fracture toughness (KIc) of unalloyed austempered ductile cast iron (ADI) was examined in room temperature ambient atmosphere. The crack growth mechanism during fracture toughness tests was determined through detailed fractographic studies. Compact tension and round cylindrical specimens were prepared from unalloyed ADI and were given four different austempering heat treatments to produce four different microstructures. Tensile properties and fracture toughness of these four differently heat-treated materials as well as cast materials were determined as per relevant ASTM standards. The results of the present investigation demonstrate that the fracture toughness of unalloyed ADI increases with increase in volume fraction of ferrite in the matrix and reaches a peak when the ferrite content of the matrix is around 65%. Both yield and ultimate tensile strength of the unalloyed ADI was found to increase with increase in volume fraction of ferrite in the matrix. The ductility of ADI, on the other hand, was found to increase with increase in volume fraction of austenite in the matrix. The crack growth mechanism was found to be predominantly by the microvoid coalescence. The crack path appears to connect the graphite nodules along the way.||Journal Article|671|12677|||8|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903620|136 23|5|1995|333-340|JTE9509|Laird G|Repetitive- and Single-Blow Impact Testing of Wear-Resistant Alloys|fracture, impact, toughness, wear, wear-resistant alloys, white cast irons|Repetitive-impact and impact toughness tests provide two distinct measures of a material's ability to resist impact-related wear phenomena. These tests are described in detail and results are presented for a variety of cast and forged wear-resistant alloys. In particular, past research at the U.S. Bureau of Mines using the ball-on-block and ball-on-ball repetitive-impact test is reviewed and the wear-related phenomena associated with repetitive impact are described. Impact toughness was measured using a modified dynamic tear test. To account for the heterogeneous and brittle nature of many wear-resistant alloys, a new tear test specimen was developed. Impact energies are presented for a variety of cast alloys and compared against literature values for static and dynamic fracture toughness of similar alloys. It is shown that repetitive-impact and single-blow impact tests allow a unique characterization of the material's behavior to crack initiation and propagation that dominate many wear environments.||Journal Article|671|12678|||8|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903621|137 23|5|1995|341-346|JTE9509|Yates JR, Ho KF, Goldthorpe MR|Mixed Mode Stress Intensity Calibrations for an Angled Crack Bend Specimen|finite element stress analysis, linear elastic fracture mechanics (LEFM), mixed mode stress intensity factors|Test specimens with angled or inclined cracks are frequently used to investigate mixed mode fatigue and fracture properties. A full three-dimensional (3-D) linear elastic finite element stress analysis has been performed for a beam with an angled single edge crack subjected to three-point bend loading. Crack angles of 45°, 60°, 75°, and 90° to the longitudinal axis of the beam have been considered. The resulting geometric correction terms to the linear elastic fracture mechanics (LEFM) mode I, II, and III stress intensity factors are presented.||Journal Article|671|12679|||6|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903622|138 23|5|1995|347-353|JTE9509|Vallee GE, Shukla A|Development of a Dynamic Load-Deflection Apparatus for Elastomeric Materials|dynamic stiffness, elastomers, impact absorber, pneumatic fastening tool|A method of experimentally determining the dynamic load-deflection behavior of elastomeric impact absorbers is developed. Particular attention was given to impact absorbers (bumpers) used in pneumatic fastening tools, and the dynamic load-deflection apparatus developed here closely replicated actual service conditions. Cylindrical specimens and actual bumpers were fabricated from epichlorohydrin and nitrile elastomers, two materials commonly used in the bumper application. The dynamic behavior of thin circular disks is also studied and brief comparison with the Split Hopkinson Pressure Bar technique is given.||Journal Article|671|12680|||7|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903623|139 23|5|1995|354-363|JTE9509|Lee Y-L, Raymond MN, Villaire MA|Durability Design Process of a Vehicle Suspension Component|computer aided engineering (CAE), critical plane, durability, fatigue, finite element analysis, knuckle|An improved methodology to quantitatively assess fatigue lives of automotive structures and to identify critical and non damaging areas for design enhancement and weight reduction is presented. The methodology of automated fatigue assessment, called CAE-FATIGUE (Computer Aided Engineering in Fatigue), combines a load-time history file with the result file from an elastic finite element analysis to estimate fatigue lives (damage contours). The CAE-FATIGUE methodology is of particular value when it is used as a proactive tool in the early design stage to reduce design iterations and prototype costs. CAE-FATIGUE is applicable to elastic finite element analysis results because the Glinka energy density method (plasticity correction approach) is used to approximate true stresses and strains from the elastic stresses. CAE-FATIGUE cannot be applied to cases where loading frequency is of importance, since the elastic stress components from all loading channels are superimposed to the resultant stresses at the same specific time. CAE-FATIGUE calculates fatigue lives based on the maximum normal stress and strain range on a critical plane on which maximum principal stresses for the entire loading history are maximized. Also, CAE-FATIGUE can generate life/damage contour plots to identify critical and nondamaging areas for design enforcement and weight reduction. This report focuses on practical aspects of designing automotive suspension components to avoid fatigue failure. The design process for a proposed front suspension knuckle is presented for illustration purposes. Critical planes highlighted with damage contours can also be used to develop "smart" and efficient prototype tests. Emphasis is placed on how to optimize the component to meet the durability criteria through mechanical life test procedure and test field endurance schedules.||Journal Article|671|12681|||10|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903624|140 23|5|1995|364-369|JTE9509|Mandel J|Structure and Outliers in Interlaboratory Studies|interlaboratory testing, outliers, regression, statistical evaluation of outliers|The current statistical analysis of interlaboratory test data involves tests of significance for outliers. In this paper we show that the use of tests of significance is faulty and we propose instead an analysis according to a row-linear model. This approach involves an examination of straight lines fitted by least squares for all laboratories against the averages over all laboratories for each level in the two-way table. By this method, a laboratory can be judged both in terms of the position of its response line when compared to other laboratories, as well as in terms of the residuals of the observed measurements from the fitted line.||Journal Article|671|12682|||6|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903625|141 23|5|1995|370-376|JTE9509|Cerra AP|Development of a New Accelerated Adhesion Test for Silicone Sealants|accelerated, adhesion, sealants, silicone, structural glazing, testing|Existing accelerated laboratory adhesion tests for silicone sealants are shown to lack the discrimination necessary to assess relative adhesive behavior. A novel test protocol is offered that enables improved discrimination by more precisely quantifying the adhesive strength of the sealant/substrate system. The method is based on the simultaneous application of both mechanical and environmental stress, in order to promote adhesive failure at loads below the cohesive strength of the bulk sealant.||Journal Article|671|12683|||7|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903626|142 23|5|1995|377-383|JTE9509|Sickels Taves LB|Elastic Strain, Creep, and Recovery in Mortars: Additional Analysis|cements, compressive strength, creep, elastic strain, limes, mortars, recovery, stresses|This paper examines the subject of elastic strain, creep, and their recoveries in mortars. An experimental program, outlined in an earlier issue of this journal, was undertaken to study the behaviors of mortars alone. Results indicated that the lime component directly and favorably affects movement in mortars. The obtained data were studied further, particularly the early minutes under compression, to determine if prior conclusions held firm and to continue to add to existing knowledge of mortars and their properties.||Journal Article|671|12684|||7|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903627|143 23|5|1995|384-387|JTE9509|Munro RG|Material Specifications of Advanced Ceramics in Corrosion Studies|ceramics, chemical composition, corrosion, database, materials specification, standards|Chemical and physical data are often reported independently in materials property databases. However, when specific applications of these data are considered, it is easily recognized that such specifications have limited utility unless the interdependence of the chemical and physical information is also reported. In this paper, the chemical and physical specification of silicon carbide, with an anticipated application to corrosion, is used as a prototypic case study of the database design requirements. With respect to corrosion, the chemical data are needed in the context of the structural information; i.e., the chemical compositions of the bulk material, the surface layers, the grain boundary regions, and regional interfaces must be distinguished. Standards for the database structure will be discussed in the context of the efficiency of the storage and retrieval system, the interdependence of chemical and physical characteristics, and the effective use of the information in subsequent applications.||Journal Article|671|12685|||4|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903628|144 23|5|1995|388-392|JTE9509|Prabhakara Rao G, Sarkar PK|A Study of the Variation of Neutron Skyshine Dose with Respect to Roof Thickness, Source Spectrum Distribution|accelerator shielding, air-scattered neutrons, neutron skyshine dose, sensitivity|Sensitivities of neutron skyshine dose calculation from particle accelerators to certain parameters like roof thickness, distance of the neutron source from the roof, and fraction of the high-energy part of the neutron spectrum were evaluated using response surface methodology. The calculations were done for distances ranging from 100 to 2000 m for various nominal values of roof thickness and for 50- and 60-MeV a-induced neutron spectra on thick tantalum targets. Roof thickness is found to be the most sensitive parameter, and next is the high-energy part of the source neutron distribution, followed by the interaction term of the two variables.||Journal Article|671|12686|||5|0|1|1995-09-01 0:00:00||||||||||0090-3973||99903629|145 23|6|1995|408-414|JTE9511|Kliger IR, Pellicane PJ|Prediction of Creep Properties of Chipboard Used in Stressed-Skin Panels|chipboard, creep properties, wood|In recent years, attention has been focused on structural stressed-skin panels (SSP) with lumber webs and sheet metal and chipboard panels as tension and compression flanges, respectively, at Chalmers University of Technology. In this study, certain mechanical and rheological properties of structural chipboard were evaluated as part of a larger project designed to predict the long-term behavior of SSP under load. Several series of tests were conducted to evaluate short- and long-term properties of urea-formaldehyde bonded chipboard. From eight full-sized panels, specimens were fabricated for use in the determination of chipboard properties. Compressive strength and modulus of elasticity (MOE) were evaluated from short-term tests. Average strength and MOE values of 20 and 4100 MPa, respectively, were obtained. The MOE value was virtually identical to that obtained from initial deformations found in subsequent creep tests, indicating that test method had no effect on MOE. Three series of long-term (11 000-h) tests were conducted under constant and similar environmental conditions and different combinations of stress-level and loading history. The results suggested that the magnitude of relative creep was greatest under lower stress levels. Two empirical models, a Clouser function without exponential terms and a power function with exponential terms (Clouser, W. S. "Creep of small wood beams under constant bending load," FPL Report 2150, U.S. Forest Products Laboratory. Madison, WI., 1959), were evaluated as predictors of the deformation-time relationship for chipboard under constant loading. The power function with the exponential terms proved to be superior at extrapolating short-term results to long-term predictions. However, both functions were relatively similar with respect to describing the long-term behavior of chipboard as the compression flange in a SSP. Measuring methods and definition of the initial deformation were found to be important, especially for predicting the relative creep factor for chipboards under different load histories.||Journal Article|672|12687|||7|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903630|146 23|6|1995|415-423|JTE9511|Parker Jr. F, Hossain MS|An Analysis of Hot Mix Asphalt Mat Density Measurements|compaction, construction, density measurement, hot mix asphalt, nuclear gage, quality assurance, quality control, variability|Hot mix asphalt mat density data collected during the 19901993 implementation of a quality control and quality assurance (QC/QA) program for pavement construction by the Alabama Highway Department (AHD) were analyzed. The influence of different measuring agencies (buyer and seller), mix type, application rate, and overlay interface conditions on the variability of nuclear gage and core density measurements was studied. The data were also used to study the influence of the several measurement variables on the ability to achieve target density. Variability and the ability to achieve target density improved as the QC/QA program was implemented, but there remained a consistent inability to achieve the target compaction level. Analysis of the significance of differences between AHD and contractor measurements was inconclusive, but AHD density measurements were consistently lower. Thicker binder mix layers had lower variability than thinner surface mix layers, but the level of compaction achieved was greater for surface mixes. Milling of the surfaces of old pavements significantly reduced the variability of density in overlay mats.||Journal Article|672|12688|||9|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903631|147 23|6|1995|424-430|JTE9511|Hsu TTC, Zhang L-X, Gomez T|A Servo-Control System for the Universal Panel Tester|concrete, deformation control, high-strength concrete, load control, reinforced concrete, servo-control system, stress-strain curves, test facilities, universal panel tester|A servo-control system has been successfully installed on the universal panel tester to study the behavior of full-size reinforced concrete panel elements. In addition to the load-control procedure, this unique testing facility is now capable of testing panels using deformation-control procedure. This servo-control system controls up to ten different servo valves with independent programming capabilities and is thus suitable for many complex applications. By using this new servo control system we were able to determine, for the first time, some material properties of reinforced concrete, including Poisson ratios, the descending branch of compression stress-strain curves, as well as the characteristics of the compressive stress-strain curves of concrete in panels with 45° steel bars.||Journal Article|672|12689|||7|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903632|148 23|6|1995|431-435|JTE9511|Zhu YT, Gao YP, Devletian JH, Manthiram A|Differential Thermal Analysis of Solid Zirconium|differential thermal analysis (DTA), multiple DTA run, phase transition temperature, specimen condition, zirconium|Several observations are made in the differential thermal analysis (DTA) test of solid zirconium (Zr) specimens. It is found that an increasing heating rate generally increases the solid-phase transition temperature for both nondeformed and cold-worked specimens, but to a different extent. Upon cycling the specimen with a constant heating rate, the phase transition temperature decreases initially during the first few runs and then remains constant. Also, holding a specimen for some time just before the phase transition during heating increases the phase transition temperature. Specimen heating history and prior cold work are also found to influence the solid-phase transition temperature.||Journal Article|672|12690|||5|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903633|149 23|6|1995|436-441|JTE9511|Lim C-T, Tan S-A, Fwa T-F|Specimen Size Effects on the Diametrical Mechanical Testing of Cylindrical Asphalt Mixes|asphalt mixes, diameter over top stone size ratio, flow, indirect tensile strength, mechanical testing, resilient modulus, size effects, stability|Specimens, 4-in. (101.6 mm), 5-in. (127.0 mm), and 6-in. (152.4 mm) in diameter, of asphalt mixtures were prepared in the laboratory to test for the specimen size effect on the resilient modulus test, the indirect tension test, and the Marshall test. Four asphalt mixtures with different top stone sizes ranging from 15.8 to 31.5 mm were used. They are B1 mix (base course), Airport, W3, and W6 mixes (wearing course). Specimens, 5-in. (127.0 mm) in size, were prepared using the same compaction equipment as 6-in. (152.4-mm) specimens, designed as by Kandhal, P.S. ("Large Stone Asphalt Mixes: Design and Construction," Proceedings of the Association of Asphalt Paving Technologists, 1990). The height of the 5-in. (127.0-mm) diameter specimen was calculated based on the diameter over the height ratios for the 4- and 6-in. (101.6- and 152.4-mm) specimens. The compaction level required was based on the energy per unit volume ratio of 4- and 6-in. (101.6- and 152.4 mm) diameter specimens. Similar measured densities of the 5-in. (127.0-mm) specimens compared with the densities of the 4- and 6-in. (101.6- and 152.4-mm) specimens indicate that the same level of compaction has been achieved. The stability ratios (stability of 6-in./5-in. specimen, stability of 6-in./4-in. specimen and stability of 5-in./4-in.) were also analyzed. They were found to be close to the theoretical values reported by Kandhal, P.S. ("Large Stone Asphalt Mixes: Design and Construction," Proceedings of the Association of Asphalt Paving Technologists, 1990). Detailed comparison of flow values for the W3 and B1 mixes were made. The B1 mix gave an unacceptable flow/diameter ratio caused by the effect of large stones. The value was too low in the case of the 4-in. (101.6-mm) specimen for the B1 mix. However, acceptable values were found for all sizes tested using the W3 mix, which had a top stone size less than 1-in. Hence, large stones (stones with diameter greater than 1-in.) in 4-in. specimens tend to produce lower deformation under loading, which also accounts for the higher modulus measured in the resilient modulus test. The influence of the ratios of the diameter of specimens to top stone size were determined for the resilient modulus and the indirect tension test. A general trend of reduction in resilient modulus and indirect tensile strength was observed. The trend suggested that 5- and 6-in. diameter specimens would give more realistic values of tensile strength and stiffness for mixes using large stones (larger than 1-in.). When larger diameter specimens are used, the results obtained from the resilient modulus and the indirect tension test are more representative of the behavior of the mixtures.||Journal Article|672|12691|||6|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903634|150 23|6|1995|442-446|JTE9511|Neunaber LM, Boivin WS, Khatri ZH, Herman BA|Water Leak Testing of Polyurethane Female Condoms|barrier products, female condoms, leakage tests, polyurethane, surfactants|This paper describes an apparatus and a technique for water leak testing of polyurethane female condoms. This test detects holes as effectively as other official FDA methods used to test barrier products such as latex male condoms and medical gloves. This rapid test simulates actual use conditions as much as possible without causing plastic deformation of the polyurethane material. Blind validation tests showed that the method detects a high percentage of holes 20 mm and larger over the entire surface of the condoms. Holes as small as 10 mm were detected with lower efficiency. Hole detection rate was highest in the bottom one third of the condom where the water pressure was greatest. The condom lubricant was shown to act as a surfactant when added to water.||Journal Article|672|12692|||5|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903635|151 23|6|1995|447-452|JTE9511|Sickels Taves LB|Creep, Shrinkage, and Mortars in Historic Preservation|creep, historic preservation, mortars, shrinkage, specification|The focus of this research is the theoretical application of laboratory statistics on creep and shrinkage in mortars to historic structures. By utilizing preexisting case studies, conclusions can be tentatively made as to how the tested mortar formulas should react in restoration projects. Mortar specifications, compiled from a variety of sources, are reviewed, and the data related to the laboratory program, enabling additional tables to be compiled and thus contributing to the long-term survival of old buildings.||Journal Article|672|12693|||6|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903636|152 23|6|1995|453-468|JTE9511|Liniecki A, Hsu TR, Li W|Fatigue Strength of Adhesive Bonded Aluminum Joints|bonded aluminum joints, fatigue strength, wind energy|This paper presents a study involving the assessment of strength of bonded joints. Coupon specimens made of 6061-T6 aluminum alloy were used in the fatigue strength testing experiments. Two sharp grooves were cut on each face of the specimen in order to simulate the cracks in the wind turbine blade. Thin patches made of the same material were adhesively bonded to the surface of the specimen, covering the grooves. All coupon specimens with and without patches were tested under oscillating bending load. Parameters such as the thickness of the adhesive material, the peeling strength and stress distribution between layers were investigated. Failures in the form of patch delamination and subsequent structure fracture were recorded and the numbers of loading cycles which caused these failures were determined. Relationships between the applied loads and the fatigue lives of tested specimens were established. On the basis of the experiments and Finite Element Analysis, an easy-to-use method for estimating the fatigue life of a real wind turbine blade was developed. The proposed method can be extended to applications involving patching of other structures subjected to repeated loads.||Journal Article|672|12694|||16|0|1|1995-11-01 0:00:00||||||||||0090-3973||99903637|153 24|1|1996|1-11|JTE9601|Chiang YJ|Robust Design of the Iosipescu Shear Test Specimen for Composites|composite materials, finite element methods, shear tests, statistical design of experiments|For the purpose of improving the accuracy of the Iosipescu shear test method, researchers have been interested in analyzing the uniformity of shear stress distribution along the notched cross section for different design configurations of specimens made of various materials. But a one-factor-at-a-time approach cannot lead to a full understanding of the shearing behavior. The statistical design of experiments based on finite element models is employed here to characterize impacts of main effects and interactions among various design factors on the uniformity of shear stress distribution along the notched cross section for two kinds of unidirectional laminae with different orthotropy: Boron/Al (boron-fiber-reinforced aluminum) and Gl/Epoxy (glass-fiber-reinforced epoxy). It is shown that (a) the notch radius and height of a specimen are significant factors, (b) the notch angle is also significant, and 90° is better than 110° in reducing the variation of shear stress distribution, and (c) some two-factor interactions are influential.||Journal Article|673|12695|||11|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903638|154 24|1|1996|12-19|JTE9601|Bian S, Maj S, Borland DW|The Unlubricated Sliding Wear of Steels: The Contact Conditions in the Sliding Zone|contact conditions, sliding wear, steel, wear testing|Previously reported studies of the unlubricated sliding of quenched-and-tempered steel pins against similarly treated rings have been supplemented by temperature measurements and tests over a range of loads and speeds. The rate of wear of a pin depends on the hardness of the countersurface; it is shown that the increase in the rate for softer rings is accompanied by a higher temperature in the pin and a rougher wear track on the ring. Attention is thereby drawn towards the conditions in the contact zone, both during running in and when a steady state has been reached.||Journal Article|673|12696|||8|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903639|155 24|1|1996|20-25|JTE9601|Kandhal PS, Wu Y, Parker Jr. F, Spellerberg PA|Precision of Marshall Stability and Flow Test Using 6-in. (152.4-mm) Diameter Specimens|large stone mixes, Marshall flow, Marshall stability, percent voids, precision statement|Earlier studies have shown that the repeatability of Marshall stability, flow, and air voids content measurements on 6-in. (152.4-mm) diameter specimens of large stone mixes is better than the repeatability on 4-in. (101.6-mm) diameter specimens. A round robin study involving twelve participating laboratories was conducted to provide information for developing a precision statement for the ASTM Test Method for Resistance to Plastic Flow of Bituminous Mixtures Using Marshall Apparatus (6 inch-Diameter Specimen) (D 5581). Difference two-sigma (d2s) limits were developed to determine acceptable single and multilaboratory differences for bulk specific gravity, percent voids, Marshall stability, and Marshall flow measurements. Analysis of other data collected during the study indicated that stability and flow measurements are not sensitive to minor differences in various 6-in. (152.4-mm) diameter breaking heads currently in use.||Journal Article|673|12697|||6|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903640|156 24|1|1996|26-31|JTE9601|Epps HH|Prediction of Single-Layer Fabric Air Permeability by Statistical Modeling|air permeability, nonlinear regression, statistical modeling, textile fabrics|Historically, it has been difficult to directly obtain accurate air permeability measurements of open-structured textile fabrics. Although measurements can be made using a nonstandard pressure differential between the two fabric surfaces, this technique may not be reliable. An alternative method of determining permeability of open-structured fabrics by extrapolation from measurements of multiple layers is used on a limited basis with instruments that may not have a full range of air permeability measurement capability. This research evaluates the accuracy of this method through comparison of statistically predicted values with actual measurements of fabrics whose permeabilities lie within the measurement range specified in the standard test method.||Journal Article|673|12698|||6|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903641|157 24|1|1996|32-36|JTE9601|Kay A|Third-Party Inspection Agency Response to Changing Needs|accreditation, conformance to standards, inspectors, quality standards, regulatory compliance, third-party inspection|The third-party inspection process is part of the commercial mechanism and as commerce changes so must independent inspection. Additionally, technological development also plays a major role. A third element is the impact of regulatory compliance; both its direct impact on commerce and its indirect impact on operations. In recent years both commerce and technology have brought about change and response. To be commercially viable, the third party inspector must be able to demonstrate strict conformance to recognized standards. How to assure this conformance has been a predominant issue with inspectors and their clients for many years. Accreditation of one kind or another, whether global in nature such as ISO 9000 or local, such as a single facility audit or a combination of both, has been the most recent vehicle for trying to reach this goal. The result of this is a tapestry of commerce and technology, interwoven with threads of compliance and conformance, both mandatory and voluntary.||Journal Article|673|12699|||5|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903642|158 24|1|1996|37-44|JTE9601|Terjimanian A, Kelly CJ|Evolution of the Internal Quality Audit at Ford Motor Company's Central Laboratory|audit, customer feedback, Deming PDCA cycle, discrepancy seriousness classification, laboratory quality, process improvement, quality audit manual, report format, turnaround time|This paper discusses the evolution of an internal laboratory quality audit which takes into account the needs and expectations of the laboratory customers, the laboratory management, and the laboratory employees. This audit has been in operation for over 15 years and its development and early years were reported at an ASTM Symposium in 1981. Since then a number of changes have been implemented to improve the effectiveness of the audit. This paper describes the creation of the auditor position with organizational independence. Developments in the Quality Audit Manual, the Laboratory Report Format Procedure and other audit standards are also reported. The paper discusses the advantages and disadvantages of using a classification system to rank discrepancies identified by the audit process. Because the underlying purpose of an internal quality audit is to improve laboratory report quality, the major beneficial role is as a learning tool. As originally structured the audit was conducted with complete anonymity of the laboratory employee. Unfortunately this anonymity constrained the reporting procedure and inhibited the universal implementation of corrective actions. After several years with no improvement in the discrepancy rate, a process change was desired. Coinciding with this need, process improvement methodology based on Deming's Plan-Do-Check-Act cycle [1] was used to develop an improved process. An audit improvement team proposed and conducted a pilot audit procedure that audited reports monthly for the natural work groups with open discrepancy reporting at work group meetings. Based on the successful pilot, management approval was obtained to implement the revised procedure and improvements in laboratory report quality as assessed by the internal laboratory quality audit are observed.||Journal Article|673|12700|||8|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903643|159 24|1|1996|45-48|JTE9601|Pao C, Clark MA, Antrim JD|National Institute for Certification In Engineering Technologies Certification: Addressing the Technician Component of Laboratory Quality|certification, competence, examination, laboratory technician, National Institute for Certification in Engineering Technologies (NICET), quality assurance|Essential to any quality laboratory operation are its technicians. A laboratory might well meet the accreditation requirements for facilities and equipment, personnel training policies, and management practices but consistent, high-quality operation cannot exist without competent personnel performing the various activities. The National Institute for Certification in Engineering Technologies (NICET) offers a means of establishing the knowledge and abilities of laboratory personnel who participate in inspection, sampling, and testing activities. NICET certifies engineering technicians by evaluating work experience, written examination performance, and recommendations by supervisors and other professionals. The NICET job task competency based certification programs were introduced in 1979. Acceptance by certificants, employers, and regulators has resulted in significant growth in both the number of persons certified and the number of new specialty programs developed. The NICET approach to certification includes two unique features. One is that the content of a specialty certification program is a collection of modules, each of which encompasses a particular job task (such as determining the air content of freshly mixed concrete by a particular ASTM standard test method) or a specific knowledge area (such as basic mathematics). The other is that the modules are categorized according to increasing levels of knowledge, experience, and responsibility. This arrangement allows the creation of written examinations that support a "career path" from an entry level technician to a senior level technician. A bonus feature of the NICET approach to testing is that because the modules are narrowly focused, the resulting examination score report can help both the technician and the employer pinpoint strengths and weaknesses. This information permits a more focused training effort rather that a "shotgun" or "A to Z" effort.||Journal Article|673|12701|||4|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903644|160 24|1|1996|49-55|JTE9601|Spellerberg PA, Trimm WL, Pielert JH|Development and Application of a Quality System Standard for Construction Materials Testing Laboratories|accreditation, construction materials, laboratory, quality, standards, testing|The American Association of State Highway and Transportation Officials (AASHTO) Accreditation Program (AAP) was initiated by AASHTO in 1988 as a tool for promoting the quality of testing in construction materials laboratories. The program currently has around 120 laboratories accredited for testing of various construction materials. In the program it became apparent that there was a need to provide specific guidance to laboratories in preparing and implementing a quality system. In response, AASHTO prepared Recommended Practice R18-92I, "Establishing and Implementing a Quality System for Construction Materials Testing Laboratories." While generally based on existing ASTM and International Standards Organization (ISO) standards, Practice R18 is much more definitive in regard to evaluation criteria for construction materials laboratories. It includes an appendix that provides illustrated examples of documents, forms, and standard operating procedures, which may be used by the laboratory in preparing a quality manual. Practice R18 has been adopted for use in the AASHTO Materials Reference Laboratory (AMRL) Laboratory Inspection Program, and became mandatory for laboratories participating in the AASHTO Accreditation Program in April 1994. This paper presents an overview of Practice R18 and its use in the AMRL Laboratory Inspection Program and the AASHTO Accreditation Program.||Journal Article|673|12702|||7|0|1|1996-01-01 0:00:00||||||||||0090-3973||99903645|161 24|2|1996|63-72|JTE9603|Vatovec M, Gupta R, Miller T|Testing and Evaluation of Metal-Plate-Connected Wood Truss Joints|heel, joints, metal-plate-connectors, splice, trusses, wood engineering|Five different types of metal-plate-connected (MPC) wood joints from a scissors truss were tested to evaluate their behavior. All joints were tested in a unique testing apparatus where in-plane loads along with moments were applied to simulate loads carried by the truss members. Strength, stiffness, and failure modes for bottom chord splice joints at web (BSJ), heel joints (HJ), crown joints (CJ), bottom chord ridge joints (BRJ), and top chord splice joints at web (TSJ) were reported. The average strengths of the BSJ, HJ, CJ, BRJ, and TSJ were 51 200 N, 49 800 N, 33 000 N, 52 300 N, and 43 100 N, respectively. The average values of the rotational stiffness were 245 440 kNmm/rad, 249 600 kNmm/rad, 103 700 kNmm/rad, and 33 800 kNmm/rad for BSJ, HJ, BRJ, and TSJ, respectively. Average transitional stiffness values were 61.7 kN/mm for BSJ, 29.2 kN/mm for HJ, and 40.2 kN/mm for BRJ. The majority of bottom chord joints failed in plate tearing, whereas top chord joints generally failed in a web member withdrawal mode. The joint stiffness data were used in a preliminary finite element (FE) analysis of the same truss, and the analytical results compared well to actual full-scale truss test results. Stiffness and strength data will be used in a future FE study.||Journal Article|674|12703|||10|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903646|162 24|2|1996|73-79|JTE9603|Tarafder S, Tarafder M, Ranganath VR|Fracture Mechanics Expressions for the Standard Chord-Supported Arc Bend Specimen|arc bend specimen, finite element analysis, fracture mechanics expressions|The linear-elastic deformation behavior of the standard chord-supported arc bend, A(B)-C, specimen has been modeled using the finite element method (FEM) in order to generate displacement and compliance data for wide ranges of geometric variables. Using these data, stress intensity factor (SIF) expressions, and crack mouth compliance (CMC) and compliance crack length (CCL) relations have been developed for the A(B)-C geometry. The accuracies of the developed fracture mechanics expressions have been determined with respect to the FEM data and were found to be within ±0.75% maximum. Against data and expressions available in the literature, the accuracies of the developed relations were evaluated and found to be satisfactory.||Journal Article|674|12704|||7|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903647|163 24|2|1996|80-83|JTE9603|Vickers T, Moukwa M|Evaluation of Test Methods and Environmental Conditions to Promote Efflorescence Formation Under Laboratory Conditions|block, cement, efflorescence, masonry, rate, relative humidity, temperature, test procedures|Several test procedures that induce formation of efflorescence on the surface of porous block specimens were investigated. This paper describes the tests that were investigated and the environmental conditions under which these tests were performed. A wicking procedure, run at an elevated temperature and low relative humidity, rapidly produces efflorescence on the surface of test samples. The rate of efflorescence formation was fastest at an elevated temperature and lower relative humidity and slowest at a cool temperature and high relative humidity. The wicking test can be used to rapidly determine the effect of changing mix proportion and the effectiveness of sealers and anti-efflorescence additives on the efflorescence potential of porous masonry units.||Journal Article|674|12705|||4|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903648|164 24|2|1996|85-90|JTE9603|Ho JC, Wu CY, Carron MJ, Maughan KP, Schmidt FJ|Titanium Cerebral Aneurysm Clips: Characterization and Performance in Magnetic Resonance Imaging and Computed Tomography|CT, imaging artifacts, MRI, titanium aneurysm clips|Cerebral aneurysm clips often cause artifacts and image distortion in magnetic resonance imaging (MRI) and computed tomography (CT). For MRI with rather strong magnetic fields B, which are near 2 tesla currently and may go higher, there are further concerns in terms of the interactions between the clips and the magnetic field. These interactions are materials dependent. Ferromagnetic materials have extremely high magnetic susceptibility c and exhibit magnetic hysteresis. When they are placed in a magnetic field not parallel with the magnetization, a torque would be exerted on them to cause deflection. Paramagnetic materials exhibit low magnetic susceptibility, and develop an induced magnetization in direct proportion to the applied field. This magnetization is always in the direction of the applied field, hence no torque would be expected. However, magnetic force always prevails as F = mcB(dB/dz), where m is the clip mass and dB/dz is the field gradient. Large forces can lead to clip movement, resulting in more risk to the patient. To reduce these complications, new aneurysm clips made of light-weight titanium metal have been developed. These clips have much-improved characteristics over the cobalt-alloy products currently being used in neurosurgery. They have significantly smaller magnetic susceptibility and lower density. Consequently, they are subjected to less magnetic force and produce much reduced artifact and image distortion in MRI and CT environments. Test results also include those from scanning electron micrographic and mechanical analyses.||Journal Article|674|12706|||6|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903649|165 24|2|1996|91-95|JTE9603|Banker JG|Commercial Applications of Zirconium Explosion Clad|clad metal, explosion clad, zirconium|Applications of process equipment manufactured from zirconium clad are reviewed. Six specific applications are summarized. These include two extensively used chemical process heat exchanger applications, three pressure vessel applications, and a kiln application. Clad fabrication processes are discussed. Clad specifications and common inspections and tests are reviewed and production test data are summarized. The compiled data indicate that zirconium-clad equipment provides reliable performance in environments in which zirconium is commonly used.||Journal Article|674|12707|||5|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903650|166 24|2|1996|96-99|JTE9603|Schutz RW|Ti Roll-Clad Plate: More Cost-Effective Plate Products for Utilizing Titanium and Zirconium Alloys in Chemical Processes|chemical process equipment, cladding, corrosion resistance, plate, roll-bonded, titanium alloys, zirconium|A new family of hot roll-bonded composite reactive metal plate products, known as Ti Roll-Clad Plate, was developed and offers significant cost savings over solid Ti Grade 7, Zr 702, Ni-Cr-Mo, and Ni-Mo alloy plate for construction of chemical process equipment. Favorable economics with these plate products stem from more efficient reactive metal utilization, a simple plate manufacturing process, and applicability of conventional fabrication/welding methods. Numerous cladding metal and backer alloy combinations are possible for these plates, permitting optimization in alloy corrosion resistance and economics for process equipment used in the chemical, petrochemical, and pharmaceutic industry.||Journal Article|674|12708|||4|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903651|167 24|2|1996|100-109|JTE9603|Ogawa A, Niikura M, Ouchi C, Minikawa K, Yamada M|Development and Applications of Titanium Alloy SP-700 with High Formability|heat-treatment, mechanical properties, microstructure, nonaerospace applications, SP-700, sporting goods, superplastic forming, titanium alloy|A new b-rich a + b titanium alloy, SP-700, was designed to improve hot workability and mechanical properties over Ti-6A1-4V alloy. The chemical composition of the alloy is Ti-4.5A1-3V-2Mo-2Fe, and particularly enhanced properties include superplasticity, hardenability, and fatigue strength. Owing to its extremely fine micro-structure and low b-transus temperature, SP-700 is superplastically formable at temperatures below 1073 K without significant increase in flow stress. More advantageously, diffusion bonding is also accomplished around this temperature. The low temperature SPF/DB process not only saves die material life and process costs, but also reduces alloy degradation from exposure at elevated temperatures, e.g., grain growth and oxidation. Isothermal and conventional hot forging are also performed better with SP-700 than ordinary titanium alloys like Ti-6A1-4V. The alloy is heat treatable and one of its many mechanical properties is that high strength over 1200 MPa is attained in solution treatment and aging condition. The advantage to this is that the moderately stable b phase tolerates air cooling for solution treatment. Thermal distortion in work pieces, which would he caused by rapid cooling, is consequently avoided. In addition, the alloy is cold workable in such cases as rolling and blanking, when annealed around 1073 K. Furthermore, fatigue life and resistance to hydrogen-assisted stress corrosion cracking are improved due to reduced aluminum content. The superior properties of SP-700 over conventional titanium alloys make new applications possible in non-aerospace fields including sporting goods, hand tools, and wrist watches. Golf drivers, with club heads made of SP-700, are sold commercially. Crampons, a new product of SP-700, withstand cold blanking and bending which reduces production costs and extends life. Due to its high forgeability, SP-700 is expected to extend its application to the production of steam turbine blades. Details of practical applications have been demonstrated together with advantages of properties and fabrication for the blades.||Journal Article|674|12709|||10|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903652|168 24|2|1996|110-118|JTE9603|Yau T-L|Performance of Zirconium and Zirconium Alloys in Organics|acetic acid, alcohols, copper effect, corrosion, formic acid, hydroxyacetic acid, lactic acid, methacrylic acid, methyl methacrylate, organic halides, organics, organometallics, phenolic resins, rayon, stress effect, urea, water effect, zirconium|Zirconium and its alloys are well known for their corrosion resistance in a broad range of inorganic and organic media. They have played a key role in advancing the production technologies of urea and formic, acetic, hydroxyacetic, lactic, and methacrylic acids, methyl methacrylate, rayon, alcohols, and phenolic resins, etc. Laboratory data and case histories are used to demonstrate the advantages of zirconium and its alloys. Compared to other engineering alloys, the use of zirconium and its alloys allows producers to make products of high quality by operating processes at higher temperatures/pressures for improved efficiency and yield. Unlike many metallic ions, zirconium produces colorless ions. Most transition metals produce ions of different colors depending on their valence state. An increasingly important advantage is that zirconium appears to he nontoxic and biocompatible. Limitations of zirconium and its alloys in organics are also discussed. They may he vulnerable in certain organic halides, such as acetylchloride, that are incompatible with water. In water-soluble organics, such as methanol, water is necessary to inhibit localized corrosion. There are impurities, such as copper ions in acetic acid, that are undesirable for zirconium and its alloys. Control measures, such as water addition and stress relieving, can be applied to zirconium equipment in certain extreme conditions.||Journal Article|674|12710|||9|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903653|169 24|2|1996|119-122|JTE9603|Schutz RW, Xiao M|Expanded Windows for Titanium Use in the Pulp/Paper Peroxide Bleach Plant|alkaline peroxide, bleaching, chelants, corrosion, hydrogen peroxide, inhibitors, pulp/paper, titanium|A corrosion database for Grade 2 titanium derived from laboratory weight-loss testing has been developed in uninhibited and inhibited alkaline 0.2-0.3 wt% H2O2 solutions at 65° to 85°C. Although titanium resistance to uninhibited hot alkaline peroxide solutions is very limited, useful resistance dramatically expands in solutions containing inhibitive species commonly existing in bleach plant processes. Effective inhibitors in descending order include Ca+2 ions, silicates, and Mg+2 salts. Addition of EDTA and DTPA chelants has no detrimental effect on Ca+2 ion inhibition unless chelant is added to excess. Based on this corrosion database, expanded application guidelines for acceptable use of Grade 2 titanium in solutions containing a maximum of 0.3 wt% H2O2 are derived at 65, 70, 80, and 85°C as a function of Ca+2 ion concentrations.||Journal Article|674|12711|||4|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903654|170 24|2|1996|123-130|JTE9603|Faccini EC, Woodbury HA|Empirical Determination of the Manufacturing Processes Which Affect EFP Liner Performance|EFP liner, liner performance, manufacturing process, Taguchi|This paper addresses a recent test series in which an L-8 Taguchi array was used to investigate the effect of various manufacturing factors on the formation of a high-performance aerostable flared explosively formed penetrator (EFP) and its subsequent effect on target. The purpose of the experiment was to develop a method of manufacturing liner blanks that would reduce variances in EFP performance. The factors investigated were: 1. Initial anneal of the material 2. Amount of work in the material prior to the initial anneal 3. Amount of material removed from the diameter of the material prior to forging 4. Forging temperature 5. Forging rate 6. Liner annealing temperature 7. Material lot number The analysis was done using 14 quality characteristics. These were: 1. EFP rod length 2. EFP necking ratio 3. Orthogonality of the flare to the rod 4. Circularity of the EFP flare 5. Sweep angle of the flare with respect to the rod 6. Flight angle 7. Entry hole diameter 8. Throat hole diameter 9. Exit hole diameter 10. Spall diameter 11. Spall volume 12. Impact accuracy 13. Overall shape (beauty) of the EFP 14. Variability between duplicates The analysis was done as a blind experiment in that the persons who were ranking the individual trials were not told what the factor levels were for the individual trial. The results of the rankings were combined and a process was chosen. This process was then used to form the verification units that confirmed the experimental results.||Journal Article|674|12712|||8|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903655|171 24|2|1996|131|JTE9603|Herbeling TG, Fee AR, Tobolski EL|Minimum Thickness Requirements for Rockwell Hardness Testing||||Journal Article|674|12713|||1|0|1|1996-03-01 0:00:00||||||||||0090-3973||99903656|172 24|3|1996|143-148|JTE9605|Annino Raymond, Villalobos Richard|Eliminating Wasteful "Cut and Try" Procedures in Gas Chromatographic Method Development Using Computer Modeling|computer aided, computer aided solutions; GC column design, computer aided; GC computer modeling, GC applications, GC method development|Computer programs that accurately predict the performance of one's chromatograph considerably shorten the interval between an analysis request and the final report by eliminating laboratory time spent in "cut and try" attempts at finding the right column and analysis conditions. Examples are presented of a program used to quickly design the optimum column or columns and conditions for multiple application scenarios.||Journal Article|675|12714|||6|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903657|173 24|3|1996|149-153|JTE9605|Brooks MW, Roy S, Uden PC, Vittum P|The Extraction and Determination of Azadirachtin from Soil and Insects by Supercritical Fluid Extraction|Azadirachtin, extraction, high-performance liquid chromatography, Japanese beetle, methanol modified, neem tree, SFE, soil, supercritical fluid extraction|Azadirachtin is a powerful anti-feedant and insect growth-disrupting compound. A primary problem with the utilization of classical extraction techniques for determining azadirachtin is the high hydrophilicity of the compound. Further, since determination by high-performance liquid chromatography (HPLC) requires measuring absorbance at 214 nm, use of methanol for extraction requires a solvent exchange since methanol absorbs in this region. This paper demonstrates the use of supercritical fluid extraction for determination of azadirachtin residues. Methanol-modified supercritical carbon dioxide is used to extract azadirachtin from soil and Japanese beetle adult and larval forms. Greater than 80% of fortified material was recovered at spike concentrations of 1 to 2 mg/g. Using this procedure azadirachtin was determined to be field stable for less than 3 months. Azadirachtin was also successfully extracted from insects showing recovery levels of 75% and greater. The inability of modified supercritical carbon dioxide to cross the insect cuticle was also demonstrated.||Journal Article|675|12715|||5|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903658|174 24|3|1996|154-160|JTE9605|Carll C, Ten Wolde A|Accuracy of Wood Resistance Sensors for Measurement of Humidity|Duff sensor, electrical resistivity, matchstick sensor, relative humidity, sorption hysteresis|This work was undertaken to evaluate the accuracy of wood resistance sensors for measurement of relative humidity and to identify sources of error in this use. Relative humidity can be expressed as a function of the logarithm of the sensor's electrical resistance and of its temperature. We found that single-point calibration of each sensor compensates for most between-sensor variation, although care must be exercised during calibration. With careful calibration readings, error in relative humidity readings made with these sensors can be limited to ±10% relative humidity under most conditions. The literature indicates that a lower degree of error than this is anticipated when electrical resistance is used to estimate moisture content measurements. Our data suggest that sorption hysteresis and sensor memory are significant contributors to this (±10%) relative humidity error.||Journal Article|675|12716|||7|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903659|175 24|3|1996|161-167|JTE9605|Gaudig W, Bothe K, Bhaduri AK, Maile K|Determination of the Geometric Profile and Stress/Strain State in the Necked Region During Inelastic Deformation at Elevated Temperatures Using a Non-Contact Measurement Technique|elevated temperature tensile testing, image analysis, necking, optical measurement of specimen profile, true stress/strain measurement|An improved testing methodology for determining the geometric profile and true stress/true strain at elevated temperatures through continuous monitoring of the specimen profile in the necked region using a video camera is demonstrated through a slow creep tensile test. The results show that the video camera is an appropriate tool for accurately monitoring specimen necking at elevated temperatures, and that the true stress and strain can be adequately determined from the specimen profile. Based on this test methodology, true strain rate-controlled creep testing can be carried out. This is essential for determining the true material parameters required for establishing appropriate constitutive equations for realistic finite element modeling.||Journal Article|675|12717|||7|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903660|176 24|3|1996|168-180|JTE9605|Mo YL, Hwang WL|Cyclic Tests on High-Strength Prestressed Concrete Frames|bridge construction, failure mode, high-strength concrete, horizontal force displacement curve, hysteretic behavior, prestressed concrete frame, seismic design|Results from small-scale models of eight high-strength prestressed concrete frames, tested under various displacement histories simulating earthquake forces are presented. The primary curves (horizontal force-displacement relationships) and the hysteretic loops are determined experimentally. Concrete strength is approximately between 50 and 60 mPa, and effective prestress is 50% of the ultimate strength of the prestressing steel. It is found that the effect of displacement history on the mechanical behavior is significant because the entire shape of the hysteretic loops is different and the prestressed concrete frames made of high-strength concrete with a slump of 25 cm may have at least a ductility factor of 8.0.||Journal Article|675|12718|||13|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903661|177 24|3|1996|181-186|JTE9605|Pandian NS, Rajasekhar C, Sridharan A|Fly Ash as a Pre-Filter Material for the Retention of Lead Ions|fly ash, lead, pH, pre-filter, retention|Clay liners have been widely used to contain toxic and hazardous waste materials. Clays absorb contaminant cations due to their exchange capacity. To improve the performance of the clay liner, fly ash, a waste material arising from the combustion of coal has been studied as a pre-filter material. In particular, the retention of lead by two different fly ashes was studied. The influence of pH on retention as well as leaching characteristics are also examined. The results obtained from the retention experiments by the permeameter method indicate that fly ash retains the lead ions through precipitation in the pores as well as onto the surface when the ambient pH value is more than 5.5, and through adsorption when the pH value is less than 5.5. It has been observed that fly ash did not release the retained lead ions when the pH value is between 3.5 and 10.0. Hence, the retention of lead ions by fly ash is likely to be permanent since the pH of most of the municipal landfill leachates are within 3.7 to 8.8. However, for highly acidic or alkaline leachates, the retained ions can get released.||Journal Article|675|12719|||6|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903662|178 24|3|1996|187-193|JTE9605|Kliger IR, Pellicane PJ|Time-Dependent Bending Properties of Lumber|long-term, stiffness, strength, stress-skin panels, timber|Research related to structural stressed-skin panels (SSP) and their component parts has been ongoing at Chalmers University of Technology. In recent years, attention has been focused on SSP with lumber webs and sheet metal and chipboard panels as tension and compression flanges, respectively. In this study, certain mechanical and rheological properties of structural lumber were evaluated as part of a larger project designed to predict the long-term behavior of SSP under load. In this study, several test series were conducted to evaluate short- and long-term properties of European redwood (called Scotch pine in North America) (Pinus sylvestris). From 22 pieces of lumber measuring 25 by 125 by 4000 mm, specimens were cut for use in several test series to determine solid wood properties. Wood modulus of elasticity (MOE), accounting for the shear effects, was evaluated from initial deflections of long-term tests. Mean MOE values of about 14 500 MPa were obtained. Four series of long-term tests were conducted under different combinations of stress level and distribution, as well as loading history. The results suggested that the magnitude of relative creep was greatest under lower stress levels. Different stress distribution (resulting from center- and third-point loading) proved to have little effect on creep behavior. Two mathematical models, i.e., power functions (Clouser function without exponential terms and power function with exponential terms) [1] were evaluated as predictors of the deformation-time relationship for lumber under constant loading. Differences in accuracy of predicting creep behavior between the two models studied were very modest.||Journal Article|675|12720|||7|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903663|179 24|3|1996|194-202|JTE9605|Obaidat MT, Al-Smadi ZA|A Modified Theodolite Instrument: Conceptual Work|3-D, photogrammetry, plane surveying, precision, theodolite|A proposed modified theodolite instrument is presented. The instrument concept, sequence of operation of measurements, and design plans are reported. The proposed instrument has a potential similar to metric photogrammetry in computing 3-D coordinates without physically touching the target point. A sliding graduated rod (arm) has been introduced to connect the upper and lower parts, each of which has a separate vertical vernier. The rod supports the theodolite head that can be extended upward an arbitrary distance, thus effectively providing a second position for the head. Appropriate angular measurements, together with the length of the extension (the rod) can be used to calculate the inaccessible distances. The instrument relies on simple trigonometric functions to measure the height of objects and the horizontal and slope distances, and to perform trigonometric leveling. Accuracy potential of the instrument has been presented based on the law of propagation of random error. The flow of operations for different measurement cases has been mathematically demonstrated. The instrument is anticipated to bypass the cost-effectiveness and technological bottlenecks between plane surveying and photogrammetric systems.||Journal Article|675|12721|||9|0|1|1996-05-01 0:00:00||||||||||0090-3973||99903664|180 24|4|1996|205-211|JTE9607|Singh SP, Cheema A|Measurement and Analysis of the Overnight Small Package Shipping Environment for Federal Express and United Parcel Service|drop height, package, shock|The purpose of this study was to measure and characterize the various impacts (free fall drops, lateral kicks, and tosses) received by packages in the overnight small parcel environments found at Federal Express and United Parcel Service. Packages instrumented with tri-axial shock data recorders were repeatedly sent through UPS "Next Day Air" and Federal Express "Priority Overnight" services and shipped from East Lansing, MI to five destinations: Monterey, CA; Atlanta, GA; Rochester, NY; Portland, OR; and Memphis, TN. A total of 100 trips were monitored and 2394 impact events recorded that measured over the trigger threshold level of 10 G. The data show that a package encounters an average of 24 shock events throughout a one-way trip consisting of 31% drops, 43.6% kicks, and 25.4% tosses. The highest free-fall drop height measured was 1.97 m (77.8 in.). The maximum kick level was 5.91 m/s (233 in./s), and the highest equivalent drop height in a toss was 0.79 m (31.4 in.). The results indicate that 95% of all drops were from less than 0.40 m (16 in.), 95% of all kicks were from less than 3.42 m/sec (135 in./s), and 95% of all tosses were from less than 0.26 m (10.5 in.) equivalent drop height. The packages received 51.1% of total impacts on edges, 42% on corners, and only 6.9% on the six flat faces.||Journal Article|676|12722|||7|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903665|181 24|4|1996|212-222|JTE9607|Aktaa J, Schinke B|Creep Lifetime Under Constant Load and Constant Stress: Theory and Experiment|AISI 316 L(N), continuum damage mechanics, creep, creep tests under constant homogenized stress, creep tests under true stress, lifetime|Creep tests are usually performed under constant load. The remarkable reduction of time to rupture due to the increase of true stress with the elongation of the specimen and with necking is estimated on the basis of the theories by Hoff, Brooklyn, and Kachanov. The influence of necking in tests under constant load and constant stress is investigated using the finite element method (PEM) with specimens containing an initial geometric imperfection. Results of the two types of tests show specimens have different sensitivities to these imperfections. To verify the theoretical statements, two types of creep tests under constant stress were performed in which the behavior of the AISI 316 L(N) austenitic steel at 700°C was investigated. In the first type, tests under constant homogenized stress, necking of the specimen was ignored. In the second type, tests under constant true stress, the mean axial stress in the minimal cross-section was held constant. To perform this type of test, an optical measuring technique was employed to determine the minimal diameter of the specimen during the test. The observed data, in particular the time to rupture, are compared with those from creep tests performed under constant load. Remarkable differences are observed. Theory and experiments confirm that problems arise if creep tests under constant load on ductile materials yielding too conservative data are interpreted with lifetime rules or continuum damage models.||Journal Article|676|12723|||11|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903666|182 24|4|1996|223-228|JTE9607|Kim JO, Slaten BL|Objective Assessment of Fabric Handle in Fabrics Treated with Flame Retardants|drapeability, fabric handle, FAST, flame retardant, flame-resistant (FR) finishes, flexural rigidity, hand, KES, stiffness, thickness, weight|Flame retardant finishes generally affect fabric handle, the tactile sensations resulting from fabric-skin contact. The subjectivity involved in the measurement of fabric handle has posed a major problem in the objective evaluation of the fabric's surface characteristics and comfort. This study investigated the effects of various flame-resistant (FR) finishes on changes in fabric handle utilizing a simple measurement technique. The nozzle extraction handle measurement method can be used as an effective objective measurement tool for textile and apparel industries to detect changes in the overall handle resulting from the processing of fibers, fabrics, or finishes. Peak handle force and slope near the peak force serve as variables to reflect overall handle. The relationships of fabric handle values to selective properties (weight, thickness, flexural rigidity, and drape coefficient) indicate that the fabric handle measured by the extraction method correlates most closely with the drape coefficient.||Journal Article|676|12724|||6|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903667|183 24|4|1996|229-236|JTE9607|Chen ET, Hughes-Dillon K, Schroeder LW|Development of Analytical Methods for Quantification of Residual Powder on "Powderless" Latex Gloves|b-cyclodextrin, analytical method, aqueous phase modifier, latex glove, residual glove powder|This paper describes the validation of an analytical method to determine the minimum amount of residual corn starch powder that can reliably be detected on "powderless" gloves. Our procedures are similar to the ASTM D 11.40 method currently under development titled "ASTM D 11.40, Section I Working Draft for Powder-free Glove Method." The various steps in the procedure were analyzed to determine their limitations and effects on the final results. The ability of the washing steps to remove residual powder from "powderless" gloves was ascertained by conducting recovery studies. An average powder recovery of 81.52% with a relative standard deviation (rsd) value of 8.12% (n = 15) was obtained by the draft ASTM D 11.40 procedure. The efficiency of the filtration and transfer steps was measured. A new device designed in this laboratory received an average yield of 1.51 ± 0.13 mg/glove (n = 15) as compared to the updated draft ASTM D 11.40 method with 0.84 ± 0.11 mg/glove (n = 15). Our new procedure gave an increase of 79% in yield with a rsd value of 8.5%. To enhance yield and powder recovery, it is crucial to rinse the glove surface effectively and reduce the washwater transfer steps. The use of b-cyclodextrin (b-CD) as an aqueous phase modifier was investigated. The results obtained with (b-CD) increased the powder recovery per glove to 102% with a pooled standard deviation (psd) of 8% (n = 30, 10 level), corresponding to a rsd value of 8% when powder recovery was in the range of 0.510 mg. With water alone, the average recovery was 89% with a psd value of 16% in the same range. However, when the range was limited to 110 mg, the powder recovery per glove when using water alone was 95% with a psd value of 14%. The 2.7 mm glass microfiber filter collects 96% of the powder applied to it. The degree of dependency to which the amount of powder on the glove affects powder recovery was studied using the relative error coefficient (rec). The rec values are less than 0.5%/mg/glove throughout the range of 0.510 mg using b-CD. With water alone in the same study range, a rec value of less than 3%/mg/glove was obtained. The correlation coefficients for percent powder recovery versus amount of powder on the glove show much less correlation over these study ranges. b-CD increased the recovery 15% and decreased the dependency of recovery on the amount of powder on the glove by 7.3-fold. The slopes and intercepts of recovered powder versus added powder were 1.01 ± 0.02 and 1.0 × 10-2 ± 1.3 × 10-1 mg for b-CD wash, and 0.95 ± 0.04 and -6.0 × 10-2 ± 2.5 × 10-1 mg for water wash in the range of 0.510 mg, respectively.||Journal Article|676|12725|||8|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903668|184 24|4|1996|237-240|JTE9607|Wolfenden A, Thomas HM, Thomas V, Chawla KK|The Effect of Fiber Coating on the Temperature Dependence of the Elastic and Anelastic Properties of a Fiber-Reinforced Borosilicate Glass Matrix Composite|fiber coating, glass matrix composite, mechanical damping, piezoelectric transducers, ultrasonic technique, Young's modulus|Young's modulus and mechanical damping were determined for two borosilicate glass matrix composites reinforced with continuous ceramic fibers for the temperature range of 20450°C using the piezoelectric ultrasonic composite oscillator technique (PUCOT). Scanning electron microscopy was also performed on the specimens. The effect of having a boron nitride fiber coating 0.2 mm thick on the properties of the composite as a function of temperature was determined. These and other measurements showed that the presence of the boron nitride coating improves the toughness of the composite without any penalty on the elastic modulus and damping characteristics.||Journal Article|676|12726|||4|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903669|185 24|4|1996|241-244|JTE9607|Singh SP, Syal VP|Leakers as a Function of Closure Type in Gallon-Size Plastic Bottles in Simulated Small Parcel Test Environment|closures, leaks, plastic bottles, small parcel shipping|This study investigated the effects of vertical vibration and drops on gallon-size plastic bottles in simulated small parcel shipping tests. Three types of round and F-style bottles were tested with different finish sizes. Three different types of closures were used on each type of bottle. Six bottles of each type were filled with water and capped with each closure type and packaged in single-wall RSC corrugated boxes with partitions. The packages were subjected to drop and vibration tests after being conditioned for 72 h at normal conditions of 23°C (73.4°F) and 50% relative humidity (RH), and accelerated conditions of 40°C (104°F) and 90% RH. The bottles were checked for application torques before testing and removal torques after testing. The results show the performance of the different types of closures and finish sizes. The larger size finish (63400) F-style bottle showed the most leaks whereas the smaller finish (33400) round-style bottles showed the fewest leaks. The bottles that were subjected to higher temperature conditioning showed more leaks and a greater reduction in removal torques.||Journal Article|676|12727|||4|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903670|186 24|4|1996|245-254|JTE9607|Marpet M|Comparison of Walkway-Safety Tribometers|coefficient of friction, force plate, tribometer, walkway safety|The friction between the floor and the pedestrian's shoe bottom is an important factor in walkway safety. There exist a number of instruments, called tribometers, for measuring this quantity. The ASTM F 13.1 Subcommittee on Tribometry, part of the ASTM F-13 Committee on Safety and Traction for Footwear, held a workshop in 1991 at Bucknell University, Lewisberg, PA. At that workshop, a number of commonly used and experimental tribometers were tested under strict laboratory conditions: The ASTM C-1028 horizontal-pull drag sled, Technical Products Model 80 drag sled, Slip Test Mark I Portable Articulated-Strut Tribometer, Slip Test Mark II Portable Inclined-Strut Tribometer, Horizontal Pull Slipmeter drag sled, Tortus dynamic drag sled, Sigler pendulum dynamic tribometer, and the James Articulated-Strut. This paper describes a number of results from that workshop.||Journal Article|676|12728|||10|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903671|187 24|4|1996|255-262|JTE9607|Cheon JS, Kim IS|Initial Deformation During Small Punch Testing|ball indentation, contact stress, initial deformation, small punch (SP) test, specimen thickness, stress and strain contour, yield stress|Initial deformation behavior during small punch (SP) testing was investigated in order to estimate yield stress using two sizes of SP specimens, 10 by 10 by 0.5 mm3 and 10 by 0.25 mm3 by finite element (FE) analysis and by experiments with heat-treated SA508 and 12Cr steels. The increase of thickness resulted in a deviation from the initial linearity of the load-displacement curve at higher loads. The deviation was attributed to different causes, namely loss of the constraint by the surrounding material and radial propagation of plastic bending deformation for 0.5 and 0.25-mm specimens, respectively. The causes for the transition of deformation mode were identical irrespective of material strength and work-hardening rate in the range of yield stress about 400 to 900 MPa. Based on the invariance of the deformation mode, a distinct linear relationship between the load at the breakaway from initial linearity and the yield stress was predicted by the FE analysis and compared with the experimental results.||Journal Article|676|12729|||8|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903672|188 24|4|1996|263-267|JTE9607|Gong Y, Norton MP|Fatigue Under Stress Cycling with Nonzero Means|cycle-dependent creep, cyclic loadings, fatigue (materials), fatigue life prediction, mean stresses|Several models are available for mean stress correction on fatigue life when nonzero means are applied. Mean value adjustment may be necessary in some cases when maximum/minimum stress causes plastic deformation. Strain-cycled fatigue tests conducted for a mild steel suggest that there may be some strain ranges where the effect of mean strain/stress is contrary to the prediction of existing models. In this study, mild steel specimens have been stress-cycled under various combinations of stress amplitudes and nonzero mean stresses. The stress amplitudes are chosen to be equivalent to the ones applied in the strain-cycled tests in a sense that the strain response is in the elastic range during the first portion of life and subsequently develops into the plastic range. Experimental results confirm observations in the study where strain cycles were applied. The cyclic softening and cycle-dependent creep process have also been studied. Possible modifications to the existing models have been suggested for the stress ranges investigated.||Journal Article|676|12730|||5|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903673|189 24|4|1996|268-271|JTE9607|Segal L|Diagnosis of Machinery by Analysis of Running Temperature Data|ambient temperature, maximum increase rate of temperature, service life friction, technical condition, thermal diagnosis, time required to reach maximum|A thermal diagnosis method is proposed for mechanisms and machinery under a transient regime, with a 1015 minute implementation time. The suggested diagnostic parameter is the ratio of the maximum rate of increase of the temperature of the mechanism during operation to the time required to reach it. The temperature pattern, processed by computer, yields the overall technical condition of the mechanism and its pre-overhaul service term. For specific mechanisms, statistical data are needed to determine the initial and limiting values of the parameter. The proposed method is applicable in production as a means of control over the technological process; in overhauls as a means of quality evaluation; and in service for detection of faults and prediction of the service life.||Journal Article|676|12731|||4|0|1|1996-07-01 0:00:00||||||||||0090-3973||99903674|190 24|5|1996|275-278|JTE9609|Kulkarni MR, Brady RP|Preliminary Characterization of Thermal Diffusivity for Carbon-Carbon Composites Through Pulsed Video Thermal Imaging|image processing, nondestructive evaluation, pulsed video thermography (PVT), thermal diffusivity|Many times complete knowledge of thermal transport properties is needed before a material can be employed in a thermal application. One property of primary concern is thermal diffusivity. What is desirable is not only the magnitude of thermal diffusivity, but also the determination of its non-uniformity. The currently used standard test method by industry is the (ASTM) Standard Test Method for Thermal Diffusivity of Solids by the Flash Method, which measures diffusivity at one point. This method also requires the destructive removal of a small sample for examination, special ad hoc machinery for surface scanning, and is not suitable for quality assessment in a manufacturing environment. There is substantial industrial demand for the nondestructive, rapid, on-line evaluation of the thermal diffusivity of an entire part's surface. Pulsed Video Thermography (PVT) is an emerging thermal wave imaging technique that shows promise for meeting those demands. In this work a brief description of the theory behind PVT and a sample application are given. Preliminary results show that the PVT thermal diffusivity values for a carbon-carbon composite plate compare favorably with those obtained by the widely used laser flash diffusivity method.||Journal Article|677|12732|||4|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903675|191 24|5|1996|279-286|JTE9609|Lytle CD, Routson LB, Thomas DP, Regnault WF, Cyr WH|Two Parameters Limiting the Sensitivity of Laboratory Tests of Condoms as Viral Barriers|condom test, latex condom, protective clothing, punctured condom, virus barrier, viruses|The practical limits of a laboratory test for evaluating condoms as virus barriers were characterized by determining virus penetration through small punctures in latex condoms. The test quantifies virus penetration through a pressurized, restrained condom filled with challenge virus. Estimation of the minimum-detectable hole (narrow slit) dimensions indicated that a limiting factor in virus transmission through such a puncture is fluid flow. The virus penetration rates decreased with time, apparently caused by the hole closing or being blocked, indicating that extending the test duration to allow more virus penetration was of limited value. Further, it was found that adsorption of virus particles during passage through a hole may limit the useful sensitivity of the test. With bacteriophage fX174 as the challenge virus, the practical limit for detecting virus penetration may be approximately 2 × 10-6 mL; with more adsorptive viruses, the test would be less sensitive.||Journal Article|677|12733|||8|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903676|192 24|5|1996|287-294|JTE9609|Zouani A, Bui-Quoc T, Bernard M|Optimal Design of a Disk-Shaped Specimen for Biaxial-Tensile Fatigue Testing|biaxial fatigue, disk specimen, finite element method (FEM), optimization criterion, testing machine|A relatively simple apparatus has been proposed for conducting biaxial-tensile fatigue tests using an annular disk specimen with a reduced testing section. It makes use of a conventional hydraulic testing machine so that the uniaxial force is converted into radial forces extending the disk specimen. Thus, a specified positive ratio of the tangential to the radial stresses can be imposed at the testing section of the disk specimen. In this paper, the optimal configuration of the specimen is investigated. A number of requirements have been identified and expressed in terms of the stresses in the testing section and their standard deviations. Afterwards, these requirements are grouped into a single performance criterion. The finite element method (FEM) is then applied to fulfill the criterion and realize the disk specimen geometry optimization for isotropic elastic materials. The results obtained from the analysis confirm the potential of the optimized specimen for the study of the material behavior under biaxial-tensile fatigue loading, in particular at high temperatures.||Journal Article|677|12734|||8|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903677|193 24|5|1996|295-301|JTE9609|Singh PR, Shukla A|A Critical Evaluation of the Performance of Optical Fiber Sensors for Monitoring Dynamic Strains|dynamic strain, optical fiber sensors, strain gage, wave propagation|An experimental study is conducted to evaluate the applicability of optical fiber sensors in measuring strains under dynamic loading conditions. Both phase modulated and intensity modulated sensors are studied. The experiments are performed to characterize the high strain rate response of these sensors and test their ability to measure changes in dynamic strain resulting from one-dimensional stress wave propagation. The stress waves are generated using both compressive and tensile gas gun setups. Then, optical fiber sensors are employed to monitor the stress wave pulse as it propagates down the bar. The output from the optical fiber sensors is compared to strain gages mounted at the same location. The results demonstrate that only localized optical fiber sensors that are bonded over the entire sensing region can be used for monitoring dynamic strain fields.||Journal Article|677|12735|||7|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903678|194 24|5|1996|302-315|JTE9609|Moran AL, Rebis RE|Structure and Property Evaluation of Large-Diameter Spray-Formed Superalloy Piping|Alloy 625, large-diameter piping, mechanical testing, metallurgical characterization, pilger rolling, roll extrusion, seawater service, spray forming, superalloys|A comparative testing evaluation program was conducted to assess the mechanical properties, metallurgical characteristics and fabricability of spray-formed Alloy 625 tubes and subsequently processed piping. Spray-formed preforms were deposited and reduced via pilger rolling or roll extrusion to produce thin-walled piping in diameters of 10.2, 20.3, and 35.6 cm (4, 8, and 14 in. nominal pipe size). Evaluations based on chemical analysis, strength, ductility, hardness, impact toughness, fatigue properties, weldability, and corrosion resistance demonstrated that spray-formed piping appears to be a viable substitute for conventionally produced Alloy 625 piping and that a minimal amount of cold working is required on the as-deposited tabular preforms in order for them to meet the specification requirements for naval applications.||Journal Article|677|12736|||14|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903679|195 24|5|1996|316-319|JTE9609|Cotterell B, Sim MC, Amrutharaj G, Teoh SH|A Fracture Test Method for Mode I Fracture of Thin Metal Materials|crack-growth resistance, fatigue crack growth, fracture toughness, Mode I fracture testing, polyimide film, thin materials, time-dependent fracture|A method of testing Mode I K dominated fractures in thin materials using a constrained short center notched tension specimen that is clamped along the loaded edge is described. Poisson's effect induces a lateral tension on the specimen that eliminates the buckling problems associated with thin materials. Furthermore, the stress intensity factor over a significant range of crack lengths and specimen geometries is dependent only on the nominal strain, making the test very suitable for crack-growth experiments under a constant-stress intensity factor. A very accurate approximate expression for the stress intensity factor is presented. A test using this method to measure the crack-growth resistance of Kapton 300HN polyimide film is described.||Journal Article|677|12737|||4|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903680|196 24|5|1996|320-323|JTE9609|Ezhov, Yuri V|Improved Indentation-Depth Method of Hardness Measurement|Brinell, depth measurement, hardness, indentation, instrument backlash, metal, penetration, reliability, reproducibility, Rockwell, test method|In the determination of the indentation hardness of a metal by pressing a ball into its surface, it is shown that the use of a modified procedure that compensates for testing-instrument backlash when measuring indentation depths gives good reproducibility of measurement, approaching the reproducibility found when measuring indentation diameters. This suggests that the need to measure the indentation diameter in the standard Brinell hardness test may be unnecessary, since comparable precision can be obtained by measuring the indentation depth, overall a simpler procedure.||Journal Article|677|12738|||4|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903681|197 24|5|1996|324-328|JTE9609|Carr DD, Strickland J, McDonald WH, Bortz S|Review of Durability Testing of Building Stone with Annotated Bibliography|bibliography, building stone, durability, physical properties, physical testing|The search for a method to test the durability of building stone has been in practice for centuries. There is no universally accepted method of testing all building stone. The differences in mineralogical, chemical, and physical properties of rocks are too great to have one test evaluate all. The standard ASTM physical tests for building stone contribute, in their own way, to the analysis of durability. The best durability test for a stone is proven use with time. In addition to examining buildings whose construction dates and sources of stone are known, the National Bureau of Standards test wall can be examined. This wall, with 2352 samples of stone, has had about 50 years of weathering in an urban environment.||Journal Article|677|12739|||5|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903682|198 24|5|1996|329-332|JTE9609|Lindblom J, Seitisleam F, Henderson PJ|Creep Testing of Steels at Very High Temperatures|creep, oxidation, temperature measurement|This paper describes changes to specimen grips and specimen design in order to creep test steels at temperatures a little below the spalling temperature and at low stresses (long times) where a large amount of oxidation occurs. High ductility and oxidation of a creep specimen often mean that the thermocouples lose contact with the specimen surface and the specimen itself cannot be removed from the grips after testing. The improvements involve the use of corrosion resistant alloys with reasonable high temperature strength for the loading bars and grips, a change in grip design and measuring the temperature inside the specimen.||Journal Article|677|12740|||4|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903683|199 24|5|1996|333-346|JTE9609|Gould G|Bias Testing: Myths, Misconceptions, and Mistakes|bias testing, normality, outliers, sample size, scale bias, Type I error, Type II error|The art and science of testing sampling systems for bias has been controversial from its beginnings, some 35 years ago. Since then it has evolved as a discipline of increasingly broad scope and complexity. Currently under consideration as a standard practice, it involves univariate, multivariate, parametric, and nonparametric statistical treatments, static and dynamic operating modes, single and two-stage tests, and matched samples consisting of single increments, sublots, and lots. Testing for bias has been encumbered with an everexpanding set of myths, misconceptions, and mistakes. The author explores the most common and grievous among them using graphics to help the reader visualize the issues.||Journal Article|677|12741|||14|0|1|1996-09-01 0:00:00||||||||||0090-3973||99903684|200 24|6|1996|0|JTE9611|Sacher A, Owens JM|International Symposium on Slip Resistance: The Interface of Man, Footwear, and Walking Surfaces||||Journal Article|678|12742|||1|0|1|1996-11-01 0:00:00||||||||||0090-3973||99903685|201 24|6|1996|353-358|JTE9611|Buczek Jr. FL, Banks SA|High-Resolution Force Plate Analysis of Utilized Slip Resistance in Human Walking|apex angle, footstrike, force plate, friction, gait, leg length, slip resistance, step length|Little controversy exists regarding the costs to society, both financial and in terms of human pain and suffering, associated with slip and fall injuries. Yet, for all the very valuable research published to date in the United States and abroad, controversy still exists regarding the biomechanics of initial foot-to-ground contact (that is, footstrike). Studies of foot kinetics have been limited by the use of force plate sensitivities chosen to capture the entire stance phase, rather than footstrike alone, necessitating the use of calculation thresholds. The present study of young adults (2 male, 2 female; 8 foot contacts each) was conducted to address these limitations. Two strain gage force plates, with sensitivities set to optimize amplitude resolution at footstrike (+100 ms), were sampled at 1000 Hz. A net shear force Fs was calculated as the vector sum of medio-lateral Fy and antero-posterior Fx shear forces. Since Fx predominantly affected the direction of impending slip, a novel shear force Fs¢ was given the amplitude of Fs and the sign of Fx. In this way, impending slips could be identified as predominantly forward or backward. Utilized slip resistance msr was calculated for each sampled instant as the ratio of Fs¢ to the normal force Fz. For comparison purposes, a geometric approximation of msr was calculated using leg length and half step length (from force plate center-of-pressure data) to derive the tangent of an "apex angle." Results showed two distinct patterns for msr over the first 100 ms of foot contact. Pattern I began with an initial backward slip tendency, with peak msr values near -0.4 occurring at approximately 10 ms. This was followed by a forward slip tendency peaking between 0.2 and 0.3, at approximately 45 ms. Pattern 1 did not seem to put the subjects at risk for slipping. Pattern 2 began with a profound forward slip tendency, with msr values above 1.0 occurring during the first 20 ms. This was followed by a brief period of backward slip tendency (|msr| < 0.3), and a second forward slip tendency (0.2 < msr < 0.3) for the remainder of the 100 ms sampling interval. Pattern 2 did seem to put the subjects at risk for an initial forward slip, though none were reported. The geometric approximations for msr typically had magnitudes near 0.4 and always predicted forward slips. We concluded that variations can be expected in foot contact patterns among normal adults. Although Patterns 1 and 2 were divided according to sex here, this may have been a coincidental finding confounded by small sample sizes, more related to shoe construction or preferred gait kinematics than to sex. Finally, geometric approximations for msr grossly oversimplified initial foot contact, and should be discontinued in favor of more accurate methodology.||Journal Article|678|12743|||6|0|1|1996-11-01 0:00:00||||||||||0090-3973||99903686|202 24|6|1996|359-367|JTE9611|Fendley AE, Marpet MI|Required Coefficient of Friction Versus Walking Speed: Potential Influences of Footwear and Walkway Surfaces|available coefficient of friction, outsole, required coefficient of friction, top-piece, tribometer, walkway safety|This paper presents data analysis for a representative subject from a pilot study where subjects walked at increasing speeds across a force plate in shoes with the top-piece/outsoles replaced by a variety of test materials, including test-foot materials commonly used in walkway-safety tribometry. The goal of this data analysis was to develop a methodology that can by used in a multi-subject experiment that combines force-plate and video data. More specifically, the objectives were: