疲劳裂纹扩展的随机模型

A STOCHASTIC MODEL OF FATIGUE CRACK GROWTH

本文从J.L.Bogdanoff提出的一种新的疲劳裂纹扩展模型出发,假定在裂纹扩展过程中存在不同的等概率均匀扩展区间,采用Z变换和其复数反演理论,推导出疲劳裂纹经任意次载荷循环后的失效概率计算的解析公式,计算结果与实验值符合较好、偏保守。

Base on J. L. Bogdanoff model of fatigue crack growth, it is assumed in the paper that during the process of fatigue crack growth, different uniform growth zones of equal probablity exist, By using Z-transform technique and its theory of inversion in complex function, a general analytic formula calculating tile failure probability of fatigue crack after any loading cycles, has been derived. The computed results is well corresponding to the experimental results and keeps safer.