冲击、疲劳、磨损是工程上造成机器零件或构件失效的三个主要敌人。从冲击的观点言,工程上大部分承受冲击负荷的机件,其所承受的冲击是属于小能量的多次重复冲击,因此,对这些机件材料抗冲击载荷的能力应该采用多次冲击试验方法来衡量。从疲劳的观点言,工程上有不少机件遭受的疲劳载荷并不完全是静疲劳,而是带有冲击性质的疲劳,因此,对这些机件所用材料抗疲劳载荷的能力应该用冲击疲劳的试 Impact, fatigue, wear and tear are the three major enemies that cause the failure of machine parts or components. From the point of view of impact, most of the mechanical parts subjected to impact load in the project bear the impact of multiple repeated impacts of small energy. Therefore, multiple impact tests on the impact load capacity of these mechanical parts materials should be adopted Method to measure. From the point of view of fatigue, there are quite a few mechanical parts subjected to fatigue loads which are not completely static fatigue but impact-type fatigue. Therefore, the fatigue resistance of materials used for these parts should be subjected to impact fatigue Test