实际结构和零部件在工作时往往受到冲击载荷的作用。如火车的起动和刹车以及速度突然改变，矿用车和装载机在装货和卸货过程中都会受到冲击的作用。而有一些机械本身就是利用冲击能量来工作的，如锻锤、凿岩机等。为了防止它们发生早期断裂，过去在设计选材时，只追求材料的冲 The actual structure and components are often subjected to impact loads at work. Such as the start-up and braking of trains and sudden changes in speed, mining vehicles and loaders are subject to shock during loading and unloading. Some machines use their own impact energy to work, such as forging hammer, rock drill and so on. In order to prevent them from early fracture, in the past in the design selection, only the pursuit of material red