多轴载荷下缺口试件疲劳寿命预测研究

基于临界平面法,在分析光滑薄壁圆管试件疲劳寿命预测模型的基础上,借助有限元应力应变分析,进一步将模型推广应用到了缺口试件的多轴疲劳寿命预测中,并利用坐标变换原理,明确了临界平面及有效循环变量的确定方法.在存在平均应力的情况下,分析了平均应力对疲劳寿命的影响,并对所建模型进行了平均应力修正.

Notched fatigue life prediction under multiaxial loading

Based on the critical plane approach and the analysis of the proposed fatigue life prediction model applied to the smoothing tubular specimen, the recently proposed multiaxial fatigue life prediction model is extended to assess multiaxial fatigue life for notched specimens. In addition, with the aid of finite element method (FEM), the orientation of the critical plane and the effective cyclic parameter are determined by using the coordinate transformation principle. In the meantime, the proposed model is modified when the mean stress is existence.