飞机结构WFD发生的概率分析

摘要

Based on the statistics in fatigue and fracture mechanics,a random variable model of crack fatigue is proposed,and the stochastic nature of crack initiation,growth and WFD is carried out by using Monte Carlo method.For specific examples,the crack initiation life,time to MSD formation and time to WFD occurrence has been obtained.Those present results are more accurate and reliable comparing with that of existing experiments.The present method has revealed the process of WFD occurrence so as to provide the fundamental of start stage of WFD inspection and aircraft operational limit.%基于断裂力学和疲劳统计学相关理论,针对无明显主导裂纹的多部位损伤（MSD）结构,提出多裂纹疲劳损伤随机模型,并利用蒙特卡洛法,编程实现了多裂纹随机萌生和扩展以及广布疲劳损伤（WFD）发生的过程。针对具体算例,得到了裂纹萌生寿命、MSD形成时间、WFD发生时间和不同应力下WFD发生的累积概率图,与现有实验数据对比。该方法真实地再现了飞机发生WFD的过程,为飞机广布疲劳损伤检查开始点的确定和飞机使用限制的建立提供了理论基础。