基于损伤力学的疲劳全寿命数值预估方法

疲劳失效是影响结构件使用安全的主要问题,对疲劳寿命进行准确预测具有重要的工程意义。基于采用平均应力修正的损伤力学演化模型,结合有限元法建立了同时考虑裂纹萌生与扩展的疲劳全寿命数值预估方法。为了验证该方法,开展了不同应力水平下铝合金开孔板试样疲劳试验与疲劳数值模拟。结果表明,基于所建立的疲劳数值分析方法能够有效预测开孔板裂纹扩展过程及疲劳全寿命,预测寿命误差带在两倍以内。

Numerical Method of Fatigue Life Prediction Based on Damage Mechanics

Fatigue failure is the main problem affecting the safety of structural members. It is of great engineering significance to predict the fatigue life accurately. Based on the damage evolution model with mean stress correction, a numerical method for fatigue life prediction considering both crack initiation and propagation was established combined with finite element method. To verify this method, fatigue tests and numerical simulations of aluminum alloy plates with holes under different stress levels were carried out. The results show that the crack propagation process and the fatigue lives can be effectively predicted by the proposed fatigue numerical method, and the error band of the predicted lives is less than two times.