基于应力不变量的多轴疲劳寿命预测方法

Multiaxial Fatigue Life Prediction Method Based on Stress Invariants

提出了一种基于应力不变量的处理多轴高周复杂载荷的疲劳寿命预测方法。该方法将剪应力等效幅值的求解与损伤估算相联系,通过考虑载荷偏量路径沿求解剪应力等效幅值时的参考坐标系各轴投影的分量来估算疲劳损伤。考虑平均应力的影响,利用多轴循环计数法和修正S-N曲线方法来预测疲劳失效循环次数。经过疲劳试验数据验证,预测结果与试验结果吻合较好。

This paper proposes a fatigue life prediction method based on stress invariants to deal with multi-axis high week complex loads.In this method,the solution of shear stress equivalent amplitude is linked with damage estimation,and fatigue damage is estimated by considering the components of load deflection path projected along each axis of the reference coordinate system when the shear stress equivalent amplitude is solved.Considering the influence of the average stress,the multiaxial cycle counting method and the modified S-N curve method are used to predict the number of fatigue failure cycles.After verification of fatigue test data,the predicted results are in good agreement with the test results.