考虑多次局部弹塑性接触变形行为、多次撞击和多次分离过程,提出了1种采用有限差分方法研究柔性结构多次弹塑性撞击问题的MCIS方法,研究了钝圆柱头刚性质量块水平撞击简支梁的过程。研究结果表明,该撞击过程实际上是1个复杂的多次弹塑性撞击过程,一般存在2个以上的明显撞击区,每个撞击区包含了形式多样的复杂的次生撞击过程。其他撞击区的冲量值与第1个撞击区的冲量值相当,其他撞击过程中损失的撞击动能的总和与首次撞击过程中损失的撞击动能相当,因此,多个撞击区和多次撞击过程将对梁的撞击物理行为产生重要影响。研究还发现,小质量块刚性体撞击时,首次撞击过程的撞击动能损失明显。在大质量刚性体撞击时,后续的多次撞击过程的撞击动能损失明显。
By considering the elastic-plastic deformation behavior of multiple contacts and the conditions of multiple impacts and multiple separations and by using the finite difference method, the MCIS method was presented to investigate the impact problem of a simply supported beam struck horizontally by a round-nosed rigid mass. The numerical simulations show that such a horizontal strike is indeed a complicated process of multiple elastic-plastic impacts. There are usually more than two impact zones in which each of them consists of complicated multiple sub-impacts. It is found that the other impact zones might occupy considerable impact impulse or even more than ones of the first impact zone. Hence, the other impact zones have significant influence on the impact responses of the beam. It is found as well that the other impacts might have considerable impact kinetic energy dissipation totally or even more than ones of the first impact. It implies that the multiple impacts are of an important role upon the impact physical behavior of the beam. The numerical investigations also show that for the light rigid mass, the first impact course will cause more kinetic energy dissipation, and for the weight rigid mass, the following multiple impact courses will cause more kinetic energy dissipation.