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.

本文旨在提出一种新的夹层梁弹塑性瞬态响应理论，包括多维弹塑性分析策略和相应的数值求解技术。材料行为遵循双线性比例硬化规则。根据应力状态的分类，获得了夹层梁结构刚度的时程更新，并随后开发了多维弹塑性动力学分析的系统程序。涉及几何和材料非线性的动态控制方程通过改进的基于 Ritz 的方法结合 Newmark-beta 技术求解。闭合线性解和有限元仿真验证了所提出的非线性理论的准确性。案例研究表明，应变硬化对夹层梁的动力响应有显着影响。夹层梁作为船体牺牲涂层的抗爆研究的应用进一步证明了当前理论的有效性。