程序载荷下疲劳可靠性分析的损伤等效递推方法

以载荷循环数－疲劳寿命干涉模型为基础，分析了程序载荷（包括随机载荷历程）作用下的疲劳可靠性问题的特点及计算方法。通过对疲劳失效过程的分析，针对复杂载荷下疲劳问题的物理本质，提出了一个以损伤等效原则转换不同载荷水平的当量循环数的可靠性递推方法，并进行了试验验证。

DAMAGE EQUIVALENT RECURRENCE METHOD OF FATIGUE RELIABILITY ANALYSIS UNDER PROGRAM LOADING

ased on load cycle fatigue life interference model,the character as well as the calculating method of fatigue reliability under program loading is analyzed。Contrary to the traditional method using a recurrence formula according to “equivalent failure probability” to transform fatigue damage under different load levels and calculate reliability, according to the analysis on fatigue process and its physical nature,a “damage equivalent” recurrence method is proposed. Experiment under multi level load condition shows that the error of the “damage equivalent” recurrence formula is equal to 32.8%,while that of the “equivalent failure probability” recurrence formula is as high as 96.8%.