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EUCLIDEAN CLUSTERIZATION OF PULSE-EXCITED COMPARATIVE MECHANICAL SPECTROSCOPY

ABSTRACT:
An alternative methodology is presented to recognize the internal state of a material, which, unlike other methods, it is not necessary to take destructive tests, in addition to the high time and costs involved. The methodology in question is summarized in a technique based on the acoustic-vibrational behaviour of metal alloys, to correlate their acoustic properties and their internal structure. As a case study, a comparison between AISI-SAE 1018 steel and two alloys, one made of aluminum and the other of brass. The specimens are used according to ASTM E1876 for the Impulse Excitation Technique (IET) test. Steel cases were tested in their existing condition and heat treatment according to ASTM E1876 and subjected to a standardized process to compare the acoustic characteristics of the same material with different microstructures. By processing the acoustic response, frequency spectra describe the acoustic behaviour obtained. By processing the acoustic response, frequency spectra describe the vibrational behaviour. The
methodology shows results that demonstrate the sensitivity of the test to microstructural changes in metallic
materials, demonstrating that the IET test is functional as an alternative method for the identification of
materials.

Key Words: Mechanical spectroscopy, Impulse excitation, Euclidean clusterization, Non destructive test