Finite element nonlinear transient response analysis of simple 2-d structures subjected to impulse or impact loads. Final report, July 1974--June 1976

This study was intended to contribute to the development of more rational practical methods for predicting the large-deflection elastic-plastic transient structural responses of structures which are subjected to transient and impact loads. Application to the structural/operational safety of nuclear power plants is considered. 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, using various approximations to the nonlinear strain-displacement relations since large deflections and rotations need to be taken into account. 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. 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