工程构件疲劳寿命估算的三维临界域法  

Three-Dimensional Critical Zone Approach for Fatigue Lifetime Prediction of Engineering Structure

作　　者：夏天翔[1] 姚卫星[2] 李旭东[3] 姜志平[1] 

机构地区：[1]南京航空航天大学飞行器先进设计技术国防重点学科实验室,南京210016 [2]南京航空航天大学机械结构力学及控制国家重点实验室,南京210016 [3]中国航空综合技术研究所,北京100028

出　　处：《南京航空航天大学学报》2014年第3期395-402,共8页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金(51275241)资助项目;江苏省普通高校研究生科研创新计划(CXZZ13_0175)资助项目;南京航空航天大学博士学位论文创新与创优基金(BCXJ13-02)资助项目;中央高校基本科研业务费专项资金资助项目

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。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.

关 键 词：航空发动机 临界域法 应力场强法 临界距离法 疲劳寿命 

分 类 号：V263.5[航空宇航科学与技术—航空宇航制造工程]