The notch characteristics of engineering components significantly impact their fatigue lives. Accurately analyzing the notch effect and size effect is of great significance for structural integrity evaluation, which provides insights into the extent of fatigue failure in engineering structures. In this paper, a new method is proposed for determining the fatigue failure region based on actual elastic–plastic stress distribution under various notch geometries and applied loads. It considers the complex mechanical behavior of the plastic effect and stress relaxation near the notch root. Furthermore, a novel weight function is employed to consider the relative stress gradient at all points within the fatigue failure region. Finally, an enhanced stress field intensity approach is developed to predict notch specimens fatigue lives utilizing experimental lives of smooth specimens. Additionally, the effectiveness of the proposed method is analyzed by predicting the fatigue lives of three distinct materials notched specimens with varying geometries and applied loads. The prediction absolute errors of the proposed approach are compared with those of the other traditional notched fatigue analysis methods. The comparative results indicated that the performance of the proposed method outperforms the other methods.

中文翻译：

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结合缺口和尺寸效应的疲劳寿命评估的增强应力场强度方法

工程部件的缺口特性显着影响其疲劳寿命。准确分析缺口效应和尺寸效应对于结构完整性评估具有重要意义，可以深入了解工程结构的疲劳破坏程度。本文提出了一种根据各种缺口几何形状和施加载荷下的实际弹塑性应力分布来确定疲劳失效区域的新方法。它考虑了缺口根部附近塑性效应和应力松弛的复杂机械行为。此外，采用新颖的权重函数来考虑疲劳失效区域内所有点的相对应力梯度。最后，开发了一种增强的应力场强度方法，利用光滑样本的实验寿命来预测缺口样本的疲劳寿命。此外，通过预测具有不同几何形状和施加载荷的三种不同材料缺口样本的疲劳寿命，分析了所提出方法的有效性。将所提出方法的预测绝对误差与其他传统缺口疲劳分析方法的预测绝对误差进行了比较。比较结果表明，该方法的性能优于其他方法。