多处损伤含孔结构随机裂纹扩展寿命预测

Prediction of Random Crack Propagation Life of Multiple Site Damage Structure Containing Holes

首先基于LY12CZ铝合金平板的中心裂纹扩展速率试验,考虑裂纹扩展速率的随机性,采用三参数对数正态分布表征Paris公式参数的分布特性,建立了LY12CZ随机裂纹扩展分析方法。利用Monte-Carlo法模拟裂纹扩展的随机性,进一步建立了多处损伤(multiple site damage,MSD)含孔结构随机裂纹扩展寿命预测模型,并将模型程序化。通过算例验证分析,该模型能够较准确预测多处损伤含孔结构裂纹扩展寿命,得到结构的失效概率,为含孔结构的MSD评估提供有效的工程分析方法。

Firstly based on the center single crack propagation experiments of LY12 CZ aluminum alloy plate and considered the random of crack propagation rate,the distribution of the Paris formula parameters were characterized with the lognormal distribution of three parameters,and a random crack propagation analysis method of LY12 CZ was established. The Monte Carlo method was used to simulate the randomness of crack propagation,and the predictive model of random crack propagation life of multiple site damage structure containing holes was further established,then programming the model. Through the example verification analysis,the model can accurately predict the random crack propagation life of pore structure containing multiple site damage,and obtain the failure probability of structure,which provides an effective engineering analysis method for multiple site damage evaluation of structure containing holes.