Fatigue life prediction of aluminum alloy materials based on surface damage and internal defects

The effects of internal defects and surface damage on fatigue life of periodically damaged specimens are analyzed by means of microscopic computed tomography and microscopic observation. A three-dimensional reconstruction model based on surface damage and internal defects was established, which was confirmed by the experimental data of fatigue damage accumulation during the stages of damage, and a statistical regression model was established by using surface roughness and stress concentration coefficient of the specimens to predict fatigue life.

通过对周期性受损样本的疲劳寿命，采用微观计算机断层扫描和微观观察的方法，分析了内部缺陷与表面损伤的影响。基于表面损伤和内部缺陷的三维重建模型得以建立，并通过损伤阶段的疲劳损伤累积实验数据得到验证。此外，利用样本的表面粗糙度和应力集中系数建立了统计回归模型，以预测疲劳寿命。