中文摘要：

临界域法将缺口附近区域中某点、线或面上的应力特征值作为材料失效的判断条件,能较合理地解释缺口效应现象,因此被认为是一类具有工程应用前景的缺口件疲劳寿命估算方法。本文首先结合三维工程结构的实际特点,详细阐述了适用于三维结构的应力场强法和临界距离法,对其中若干参数进行了准确定义和描述。然后,本文分别使用这两种方法和名义应力法对某型航空发动机轮盘进行了疲劳寿命估算。结果表明,本文给出的适用于三维结构的应力场强法、临界距离法能很好地预测航空发动机轮盘的疲劳寿命;而且相比于名义应力法,预测效果更好。

英文摘要：

For critical zone approach,the stress eigenvalues of a certain point, line or area in the vicinity of notch are used as the failure criteria. This paper presents a reasonable explanation for notch effect. Therefore, critical zone approach is considered as a fatigue life predicton method for notched specimens with a promising prospect in engineering application. The stress field intensity approach and the theory of critical distances for three-dimensional structures are first elaborated considering three-dimensional engineering structure characteristics. Several parameters are accurately defined and described. Then the two methods and the nominal stress approach are applied to predicting fatigue life of an aero engine disc. The results indicate that the proposed stress field intensity approach and the theory of critical distances for three-dimensional structures provide an excellent prediction on fatigue life. The two methods have a better prediction effect than the nominal stress approach.