Nonlinear transient response of elastoplastic sandwich beam

This paper aims to propose a new theory on the elastoplastic transient response of sandwich beams under large displacement with moderate rotation, including an analysis strategy for multi-dimensional elastoplasticity and the corresponding numerical solving technique. The material behaviors follow the bilinear proportional hardening rule. According to the classifications of stress statuses, the updated structural stiffness of the sandwich beam in time history is acquired and a systematic procedure for the multi-dimensional elastoplastic dynamic analysis is subsequently developed. The dynamic governing equations involving geometric and material nonlinearities are solved by a modified Ritz-based approach, in association with the Newmark-beta technique. The closed linear solution and the finite element simulation validate the accuracy of the proposed nonlinear theory. Case study reveals that the strain hardening has significant effects on the dynamic response of sandwich beams. The application to the blast-resisting study of sandwich beams as sacrificial coatings on ship hulls further proves the effectiveness of the current theory.