基于临界面法的三参数多轴疲劳损伤模型

基于临界平面方法,提出一种能适用于拉-扭加载的多轴疲劳损伤模型.新的模型采用应力与应变的三参数相结合形式,不仅考虑了当前循环内临界面上最大剪应变范围和正应变变程对多轴疲劳损伤的贡献,还顾及了非比例附加强化效应和平均应力对多轴疲劳寿命的影响.该模型预测精度较高且本身不含有材料常数,便于实际工程应用.最后,将提出的多轴疲劳寿命估算模型结合Inconel 718钢、高温GH4169合金和高温Haynes 188合金等3种材料的多轴疲劳试验进行寿命预测验证,预测结果与试验结果吻合较好.

Multiaxial Fatigue Damage Model With Three Parameters Based on the Critical Plane Approach

Based on the principle of critical plane approach,a multiaxial fatigue damage model is proposed in this paper,which can be applied to axial-torsional loading.Three parameters on the critical plane are considered in this model,which takes into account not only the maximum shear strain range and normal strain range on the critical plane,but also the effects of the additional cyclic hardening caused by the non-proportional loading and the mean stress on the fatigue life.Additionally,its accuracy for life evaluation is relatively high,and it is convenient for engineering application because of no material constants.The capability of fatigue life prediction for the proposed fatigue damage model is verified by the experimental data from constant amplitude axial-torsional loading of Inconel 718 steel,GH4169 alloy,and Haynes 188 superalloy.Prediction results agree well with the experimental results.