基于裂纹萌生期限的典型零件剩余寿命预测

摘要

将有限元分析方法与疲劳寿命预测相结合，以曲轴为对象，对循环载荷导致的疲劳断裂进行了研究。以实际裂纹检测精度定义的疲劳裂纹萌生极限尺寸为计算标准，通过ABAQUS有限元分析计算整体应力应变，采用子结构分析由名义载荷得出的局部最大名义应力载荷谱，结合Ohij疲劳寿命法则准确计算出裂纹萌生期限，实现了基于裂纹萌生的剩余寿命预测。%Combining the method of finite element analysis with fatigue life prediction, fatigue trac ture led by cyclic load was studied with crankshaft as the object. Based on the actual crack detection accuracy of the fatigue crack initiation limits as the size of the computational standard,the comprehen sive stress and strain were obtained through finite element analysis, then using substructure analysis the spectrum of local maximum load nominal stress was calculated, integrated with fatigue life law the period of the crack initiation was goten precisely. The rest life prediction was realized based on the crack initiation. It provides a method to predict the rest of life for low stress high cycle fatigue led by cyclic load.