基于Gamma退化过程的机械零部件可靠性灵敏度方法

Reliability Sensitivity Analysis Method of Mechanical Parts Based on Gamma Process Strength Degradation

采用随机变量描述初始强度的不确定性,利用Gamma过程描述强度退化过程.在此基础上,运用摄动法、四阶矩法和Edgeworth级数方法,解决了随机参数服从任意分布的可靠度计算问题.基于矩阵微分方法,推导出关于随机变量均值和方差的可靠性灵敏度的计算公式.以螺栓为例对所提方法进行验证,结果表明该方法可有效地解决机械零部件强度退化时的可靠性灵敏度问题.

The uncertainty of the initial strength was described by a random variable, and the evolution process of the strength degradation was regarded as the Gamma process. Then the perturbation method, the fourth moment and Edgeworth series method were used to solve the problem of reliability calculation with random parameters of arbitrary distributions. Matrix differential-based formulas for calculating the reliability sensitivity with respect to the mean and the variance of the random variables was derived based on the matrix differential method. The reliability analysis of the bolts was taken as an example to verify the proposed method. The results showed that the method can effectively solve the problem of the reliability sensitivity of mechanical parts with strength degradation.