Abstract Fatigue life prediction is one of the most important problems in design of industrial components made of defect-containing materials. Not only can defects existing in these materials significantly affect the mechanical properties especially fatigue behavior, but they also lead to considerable scatter in fatigue life. Therefore, a robust design methodology for these materials should consist of statistical evaluation of defects and prediction of fatigue life using an appropriate defect-based model. In this study fatigue life analysis is performed using crack growth models. A small crack growth model is proposed which can consider the effect of mean stress as well as overall plastic deformation. Fatigue life predictions are performed using the defect size measured from the fracture surfaces, as well as the maximum defect size estimated by extreme value statistics within the stressed volume. The predicted fatigue lives based on the proposed model are in very good agreement with the experimental fatigue lives. Discussions of fatigue limit, mean stress, and the effect of defect parameters on fatigue life are also included.

中文翻译：

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基于孔隙率特征的铸铝合金疲劳寿命预测

摘要 疲劳寿命预测是含缺陷材料工业零部件设计中最重要的问题之一。这些材料中存在的缺陷不仅会显着影响机械性能，尤其是疲劳行为，而且还会导致疲劳寿命的相当大的分散。因此，这些材料的稳健设计方法应包括使用适当的基于缺陷的模型对缺陷进行统计评估和预测疲劳寿命。在这项研究中，疲劳寿命分析是使用裂纹扩展模型进行的。提出了一种可以考虑平均应力和整体塑性变形影响的小裂纹扩展模型。使用从断裂表面测量的缺陷尺寸进行疲劳寿命预测，以及通过应力体积内的极值统计估计的最大缺陷尺寸。基于所提出模型的预测疲劳寿命与实验疲劳寿命非常吻合。还讨论了疲劳极限、平均应力和缺陷参数对疲劳寿命的影响。