一、概述锻压机械的大部分零部件都是在交变载荷下工作,它们往往是在经受了几十万乃至几百万次载荷后而破坏的.因此,疲劳破坏是它们失效的主要方式,且多为高周疲劳.机械零件在交变载荷下的疲劳破坏与静载下的破坏有本质的差别.静强度设计中使用的材料强度指标如σ_s、σ_b等,在疲劳设计中已不适用.因此,疲劳设计理论已日益成为一门专门的学科.锻压机械主要零部件疲劳破坏的实例有很 I. Overview Forging machinery most of the components are working under alternating load, they are often subjected to hundreds of thousands or even millions of times under load and therefore fatigue failure is the main way they fail, And most of them are high cycle fatigue.The fatigue damage of mechanical parts under alternating load is essentially different from the damage under static load.The material strength indexes such as σ_s and σ_b used in the design of static strength are not applicable in fatigue design Therefore, the theory of fatigue design has increasingly become a specialized discipline.Examples of fatigue failure of the main components of forging machinery are very