Development of Space-Time Finite Elements for Nonlinear     Transient Response of Flexible Structures
{'Code': '07030000', 'Directorate': {'Abbreviation': 'ENG', 'LongName': 'Directorate For Engineering'}, 'Division': {'Abbreviation': 'CMMI', 'LongName': 'Div Of Civil, Mechanical, & Manufact Inn'}}
{'SignBlockName': 'Devendra P. Garg', 'PO_EMAI': None, 'PO_PHON': None}
This project focuses on the computational difficulties associated               with steep gradients in the velocity and displacement fields in                 structures subjected to impulsive loadings.  The conventional                   finite element approach would suggest creating a finer element                  mesh around the areas with large gradients, but since the                       gradients move through the structure, such a procedure is not                   efficient.  This could be solved by increasing the number of                    finite elements throughout the structure, but it would be                       computationally impractical to do so.  An alternative approach                  would call for formulation of the problem in terms of a modal                   analysis.  The large number of modes thereby required to model                  the structure implies similar computational difficulties.  A                    third alternative, finite differences in space and time is                      computationally inefficient for use in design oriented analysis.                The approach adopted herein, finite elements formulated in the                  space time domain, offers the possibility of overcoming these                   computational problems.  Three classes of physical systems will                 be analyzed including a string under constant tension, a string                 under nonuniform tension, and a linear Timoshenko beam.  For the                string models, initial value problems including those for which a               wave travels down the string will be solved as well as those                    involving moving load and impulsive load problems.  For the                     Timoshenko beam, moving loads and moving constraint problems will               be considered.  The project comprises three phases including: (1)               determining shape functions and convergence criteria for finite                 elements that cut across space and time; (2) computing solutions                for string problems and study of convergence properties, and set                up of the general solution for a space time finite element                      formulation for Timoshenko beams; and (3) determining solutions                 for beam problems with moving loads and moving constraints.  The                impact of this research will be on the methods of analysis for                  systems with moving loads or constraints, deployment problems,                  and flexible manipulator arms.
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{'Name': 'Georgia Tech Research Corporation - GA Tech Research Institute', 'CityName': 'ATLANTA', 'ZipCode': '303186395', 'PhoneNumber': '4048941222', 'StreetAddress': '926 DALNEY ST NW', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Georgia', 'StateCode': 'GA', 'CONGRESSDISTRICT': '05', 'CONGRESS_DISTRICT_ORG': 'GA05', 'ORG_UEI_NUM': 'EMW9FC8J3HN4', 'ORG_LGL_BUS_NAME': 'GEORGIA TECH RESEARCH CORP', 'ORG_PRNT_UEI_NUM': 'EMW9FC8J3HN4'}
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[{'Code': '1442', 'Text': 'CONSTRUCTION AND INFRASTRUCTUR'}, {'Code': '1445', 'Text': 'DYNAMICS & CONTROL'}]
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8822003.xml'}