飞机结构MSD失效概率的敏感性分析

考虑到飞机结构的多部位损伤（MSD，Multiple Site Damage）结构裂纹萌生位置的不同可能对结构的安全性能存在影响，分析结构失效概率对各应力集中部位裂纹萌生寿命和应力的敏感性，量化其对结构安全性能的影响.裂纹萌生寿命采用对数正态模型，通过定义核函数建立MSD结构失效的敏感性分析模型， 采用Monte-Carlo模拟计算概率敏感度.该方法利用Monte-Carlo概率分析的结果，只需增加少许计算量即可得到失效概率对参数的敏感度.将该方法应用于共线多孔板分析，得到了给定寿命下失效概率对各关键位置应力和裂纹萌生寿命对数均值的敏感度，从而确定了对结构安全影响最大的位置. 

Probabilistic sensitivity for failure of multiple site damage in aircraft structures

Different structure crack initiation position may affect the performance of the structural safety in structures containing multiple site damage. Considering that, a method to analyze the sensitivity of failure probability with respect to the stress and crack initiation life on each site was proposed to quantify their impact on the structural safety performance. A probabilistic sensitivity analysis model for failure of multiple site damage in aircraft structures was put forward using a kernel function. The Monte-Carlo simulation results in probability analysis were used to obtain the probabilistic sensitivity with a slight increase in the amount of calculation. This method was applied in analysis of a collinear porous plate, and the site with greatest impact on structural safety was identified using the probabilistic sensitivity.