典型缺口件疲劳寿命分析方法

Typical fatigue life analysis approaches for notched components

通过对典型缺口件疲劳寿命分析方法进行系统的回顾,按照疲劳缺口效应描述参数的不同将缺口件疲劳分析方法划分为3类:局部应力应变法、应力梯度法和临界域法.结合4种不同缺口几何下的LY12CZ铝合金缺口件的低周疲劳试验数据,对上述3类方法进行的验证对比可以发现:考虑了应力梯度和应力场分布的方法(如临界域法和应力梯度法)对缺口件疲劳寿命的预测结果与试验结果吻合较好而局部应力应变法预测精度较差,其中应力场强法还能够正确地预测疲劳破坏位置.

Some commonly used fatigue life analysis approaches for notched components were systemically reviewed.According to different descriptions of the notch effect,the fatigue life analysis approaches for notched component were classified into three categories,namely,local stress-strain approaches,stress gradient approaches and critical zone approaches.The capability of each approach was discussed and experimentally checked by four groups of LCF（low cycle fatigue） test data of LY12CZ aluminum alloy under different notch geometry.It’s found that the predictions with regard to stress gradient and distribution of stress field（e.g.critical zone approach and stress gradient approach） show a good agreement with test data as well as the stress field intensity approach can predict the correct failure location,while the local stress-strain approach showes poor fitness and low accuracy.