一、前言在生产实践中经常遇到承受多次小能量冲击载荷的机件,这类机件在使用中典型的失效形式是截面突变处发生早期断裂(排除截面突变处圆角过渡和表面粗糙度较差等因素)。从其损伤积累的破坏过程来看属疲劳型。但因是冲击载荷,断裂受加载速度、冲 I. Introduction In the production practice, it often encounters parts subjected to many small energy impact loads. The typical failure mode of such parts in use is the early fracture at the section abrupt change (excluding the corner transition at the section abrupt change and the surface roughness Poor degree and other factors). It is a fatigue type from the damage process accumulated by its damage. But because of the impact load, fracture by the loading speed, red