在考虑裂纹闭合效应及熔覆残余拉应力对疲劳损伤影响的情况下,对Chaboche提出的非线性连续疲劳累积损伤模型进行了修正,得到了激光熔覆试件疲劳寿命评估模型,并由激光熔覆试件对称循环拉压疲劳试验、静拉伸试验、残余拉应力检测等试验数据得出了修正模型的相关参数。通过二级加载(高低加载和低高加载)拉压疲劳试验对寿命评估模型进行了验证,结果表明模型计算值和试验值吻合良好,证明修正后的模型能够准确预测激光熔覆试件的疲劳寿命。
Chaboche′s model of nonlinear continuum fatigue damage is modified based on the impact of crack closure and residual tension stress of laser cladding effect on fatigue damage. A cumulative fatigue damage model is developed accordingly to predict the fatigue life for laser cladding component. The related parameters are concluded from fully reversed fatigue experiment and static tension test and residual tension stress test. To verify the proposed model, tension-compression fatigue tests under two stage loadings(high-low loading and low-high loading) are carried out. The results show that the calculated value and experimental value are in good agreement.It has been proved to be an efficient method to predict the fatigue life of the laser cladding component.