关于多冲试验方法的评价

COMMENT ON REPEATED IMPACT TESTS

在综合分析多冲载荷的特性及有关多冲试验的文献资料后,得出多冲载荷兼有循环载荷和冲击载荷的特点。循环载荷的特点,导致材料在多冲载荷下的破断过程,不同于一次摆锤冲击载荷下的破断过程;多冲载荷下材料的破坏过程,是循环载荷作用下的裂纹萌生及扩展过程,属于疲劳的范畴。多冲试验有别于一冲试验。但冲击载荷的特性,又导致应力波的传播和叠加,并使加载速率的作用变得重要起来,与一般的疲劳试验相比,具有其独特的性质。多冲试验不能被疲劳试验所代替。

Analyzing and summing up the literatures on repeated impact load character and test, the writers hold that the repeated impact load not only has repeated load character but also has impact load character. Repeated load character makes material fracture procedure under repeated impact load differ from that under impact ductility load. The material fracture procedure under repeated impact load is the procedure of erack initiation and propagation under repeated load. It is a fatigue. Repeated impact test is different from non-impct fatigue test. Impact load character leads to the propagation and repeated addition of stress wave, and the rate of strain turns to be important. Comparing with non-impact test, it has special character. Repeated impact test can't be replaced by nonimpact fatigue test.