非正态变量可靠性灵敏度分析方法.pdfVIP

Journal of Mechanical Strength 2008 ,30 ( 1) :052057 非正态变量可靠性灵敏度分析方法 REL IABIL ITY SENSITIVITY METHOD FOR NONNORMAL VARIABL E 宋 　军 　吕震宙 (西北工业大学 航空学院 ,西安 710072) SON G J un 　LU ZhenZhou ( School of A eronautics , N orthwestern Poly technical University , X i ′an 710072 , China) 摘要 　基于极限状态函数矩估计的失效概率计算 ,提出一种非正态变量可靠性灵敏度分析的新方法 。推导极限状 态函数的矩对非正态基本变量分布参数的偏导数 ,并利用失效概率与极限状态函数矩的关系 ,推导失效概率对非正态基 本变量分布参数的偏导数 ,从而得到非正态变量可靠性灵敏度 。用文中方法和改进的一次二阶矩法同时分析对数正态 变量的可靠性灵敏度 ,验证文中方法的正确性 ;最后运用其方法计算失效概率对指数和 Weibull 分布参数的灵敏度 。 关键词 　可靠性 　非正态变量 　概率分析 　一次二阶矩法 　参数灵敏度 　矩方法 中图分类号 　O213 . 2 　TB114 . 3 Abstract 　Based on the moment estimation of limit state function for failure probability calculation , a new reliability sensitivity method is presented for limit state function with nonnormal variables. The partial differential of the moment of the limit state function to distribution parameters of basic variables is derived. By use of the relationship of the failure probability and the moment of the limit state function , the partial differential of the failure probability to the distribution parameters of basic the nonnormal variables is derived fur thermore . Hereby , the reliability sensitivity is obtained for the nonnormal variables. Compared with the reliability sensitivity based on the first order and second moment method , a logarithm normal illustration is used to demonstrate the rationality and the precision of the presented reliability sensitivity method. At last , the presented method is em