疲劳剩余寿命分布的当量关系及可靠性计算方法

The Equivalent Life Distribution and Fatigue Reliability Calculation Method

通过大量试验分析了两级载荷作用下疲劳寿命分布参数的变化规律，研究了非恒幅循环载荷下的疲劳强度可靠性问题的特点及计算方法，通过对疲劳过程中剩余寿命分布规律的分析和研究，针对程序载荷作用下疲劳过程的物理本质，提出了一个以载荷循环数一疲劳寿命干涉模型为基础，以“损伤等效原则”计算不同载荷水平之间的当量循环次数，并充分考虑不同载荷历史下剩余寿命分布参数的变化的疲劳可靠性计算方法。

The variation behavior of fatigue life distribution parameters is analyzed experimentally undertwo-level cyclic loads,and the characteristics and calculation method of fatigue reliablilty are studied. Differing from the conventional' conditional probability-equivalent life' method calculating the equivalent cyclenumbers between different stress levels on 'equivalent failure probapility' basis, the present paper developsan 'equivalent life distribution' method based on the rule of equivalent damage and variation behavior of fatigue life distribution parameters under complex loading. Test result under multi-level loads shows that thismethod is satisfactory.