刚性质量对简支梁的多次塑性撞击

Multiple Plastic Impacts of Simply Supported Beam Struck by Rigid Mass

基于刚塑性动力学理论和单轴压缩弹塑性接触模型,对刚性质量水平撞击简支梁的问题进行了理论研究。研究结果表明,刚性质量撞击简支梁的过程是一个复杂的多次塑性撞击过程,存在2个明显的撞击区。每个撞击区包含复杂的次生撞击过程。两个撞击区的撞击冲量相当,第二撞击区中的多次撞击过程将对梁的撞击物理行为产生重要影响。撞击物质量对撞击动能损失率有明显的影响,随着质量的增加,首次撞击过程的动能损失率减小,后续撞击的动能损失率增加。通过与动力有限元的计算结果的对比研究表明,在理论上大为简化的塑性动力学理论,能够描述复杂的多次塑性撞击过程,刻划具有明确物理意义的塑性变形状态,对结构的主要撞击响应特征的预测合理。

By employing the uniaxial compression elastic-plastic contact model,the impact problem of a simple supported beam struck horizontally by a rigid mass was investigated within the framework of rigid plastic theory.The numerical simulations show that such a horizontal strike is indeed a complicated process of multiple plastic impacts.It finds that there are two obvious impact zones in the whole impact course and each impact zone consists of complicated multiple sub-impacts.It finds as well that the second impact zones might occupy considerable impact impulse or even more than that of the first impact zone.Hence,the second impact zone has significant influence on the impact responses of the beam.It implies that the multiple impacts play an important role on the impact physical behavior of the beam.The numerical investigations show that with the increase of the rigid mass,the first impact will cause less kinetic energy dissipation,whilst the following impacts will cause much more kinetic energy dissipation.The comparison of the numerical simulations of dynamic finite element method with the presented rigid plastic theory illustrates that the rigid plastic theory can be applied to the analysis of multiple plastic impact phenomenon,describing plastic states of structure in physical mechanism and evaluating main characteristics of impact dynamic responses.