Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads

Originally presented as the first author's thesis, (M.S.) in the M.I.T. Dept. of Aeronautics and Astronautics

Bibliographic Details
Main Authors: Rodal, José J. A., Witmer, Emmett A.
Format: Technical Report
Language:en_US
Published: MIT Energy Lab 2005
Subjects:
Online Access:http://hdl.handle.net/1721.1/27252
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author Rodal, José J. A.
Witmer, Emmett A.
author_facet Rodal, José J. A.
Witmer, Emmett A.
author_sort Rodal, José J. A.
collection MIT
description Originally presented as the first author's thesis, (M.S.) in the M.I.T. Dept. of Aeronautics and Astronautics
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institution Massachusetts Institute of Technology
language en_US
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spelling mit-1721.1/272522019-04-09T17:46:38Z Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads Rodal, José J. A. Witmer, Emmett A. Finite element method Structural dynamics Transients (Dynamics) Girders Originally presented as the first author's thesis, (M.S.) in the M.I.T. Dept. of Aeronautics and Astronautics This study was intended to contribute to the development of more rational practical methods for predicting the transient responses of structures which are subjected to transient and impact loads. Attention is restricted to the global structural response; local (or stress-wave- induced) response is not included. The use of higher-order assumed- displacement finite elements (FE) is investigated to seek more efficient and accurate strain predictions; these studies were carried out for 2-d structural deformations typical of beams and curved rings to minimize cost and labor. These studies were done in conjunction with the use of various approximations to the nonlinear strain-displacement relations since large deflections and rotations need to be taken into account. Transient large-deflection elastic-plastic structural response predictions are made for these various FE models for impulsively-loaded beams and a free initially-circular ring, for which high quality experimental measurements of strains and deflections are available. From comparisons of (a) predictions with each other for the various FE models investigated and (b) predictions vs. experimental data, it appears to be more efficient for the same number of degree-of-freedom (DOF) unknowns to use the simple 4 DOF/node elements rather than fewer of the more sophisticated 8 DOF/node elements although the latter provide a physically superior and more realistic distribution of strain along the structural span at any given time instant compared with the use of the 4 DOF/N elements. Comparisons of measured with predicted transient strain and final deformation of a thin aluminum beam with both ends clamped and impacted at midspan by a 1-inch diameter steel sphere show very good agreement. Extensions to the present analysis to accommodate more general types of fragments and fragment-impacted structures are discussed briefly. 2005-09-15T14:36:00Z 2005-09-15T14:36:00Z 1976 Technical Report 04065249 http://hdl.handle.net/1721.1/27252 en_US MIT-EL 76-004 10873215 bytes application/pdf application/pdf MIT Energy Lab
spellingShingle Finite element method
Structural dynamics
Transients (Dynamics)
Girders
Rodal, José J. A.
Witmer, Emmett A.
Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title_full Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title_fullStr Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title_full_unstemmed Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title_short Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads
title_sort finite element nonlinear transient response analysis of simple 2 d structures subjected to impulse or impact loads
topic Finite element method
Structural dynamics
Transients (Dynamics)
Girders
url http://hdl.handle.net/1721.1/27252
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