The dynamic plastic response for a pinned rigid plastic beam subjected to an arbitrary impulsive distributed load was investigated . the effect of strain hardening and strain rate sensitivity was ignored . the yielding curve was assumed to be rectangular 采用刚塑性假定,忽略应变强化效应和应变率的效应并考虑由于有限变形而导致的轴力的影响,研究任意时间历程冲击载荷作用下简支梁的塑性动力响应问题。