提出了一种新的机理模型,该模型以喷丸处理构件裂纹扩展分析为基础,说明喷丸处理对机械构件疲劳寿命预测的影响。在裂纹扩展过程中,引入了表征表面粗糙度影响的渐进应力强度因子,并用时变残余应力函数改变裂尖应力比。用试验数据验证机理模型的有效性,结果表明,试验数据和模型预测非常吻合。
A new mechanism modeling is proposed in this paper to explain the shot peening effect on fatigue life predictions of mechanical components. The proposed methodology is based on the crack growth analysis of shot peened specimens. An asymptotic stress intensity factor solution is used to include the surface roughness effect and a time varying residual stress function is used to change the crack tip stress ratio during the crack propagation. A wide range of experimental data is used to validate the proposed mechanism modeling. Very good agreement is observed between experimental data and model predictions.