Abstract Notch features often raise critical influences on fatigue lives of engineering components, which deserve particular attentions for ensuring their structural integrity and reliability. The theory of critical distance provides a simple way to evaluate fatigue lives of notched components without extracting complicated stress fields within the notch vicinities. In this study, a probabilistic model for deducing fatigue life distribution of notched components is established by coupling the Weibull distribution with the theory of critical distance. In addition, the influence of size effect on critical distance values and predicting performance is characterized by two strategies, i.e. average approach and highly stressed volume-based approach. Experimental data of low carbon steel En3B and Al 2024-T351 were utilized for model validation and comparison. Predicted P – S – N curves indicate that the predicted scatter bands using highly stressed volume approach yield better correlations with experimental results than that by the average approach.

中文翻译：

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使用临界距离理论在尺寸效应下对缺口部件进行概率疲劳评估

摘要 缺口特征往往对工程构件的疲劳寿命产生重要影响，为确保其结构完整性和可靠性，应特别注意。临界距离理论提供了一种简单的方法来评估缺口部件的疲劳寿命，而无需提取缺口附近的复杂应力场。本研究将Weibull分布与临界距离理论相结合，建立了推断缺口部件疲劳寿命分布的概率模型。此外，尺寸效应对临界距离值和预测性能的影响具有两种策略，即平均方法和基于高应力体积的方法。低碳钢En3B和Al 2024-T351的实验数据用于模型验证和比较。预测的 P – S – N 曲线表明，使用高应力体积方法的预测散射带与实验结果的相关性比平均方法更好。