航空发动机燃油管路概率疲劳极限测试方法  

Test Method for Probabilistic Fatigue Limit of Aviation Engine Fuel Tubes

作　　者：刘伟[1] 韩天宇 吕朋蓁 郭闯 Liu Wei;Han Tianyu;Lyu Pengzhen;Guo Chuang(Northwestern Polytechnical University,Xi’an 710129,China;AECC Sichuan Gas Turbine Research Institute,Chengdu 610599,China)

机构地区：[1]西北工业大学,陕西西安710129 [2]中国航发四川燃气涡轮研究院,四川成都610599

出　　处：《航空科学技术》2023年第12期59-68,共10页Aeronautical Science & Technology

基　　金：航空科学基金(2018ZB53016)。

摘　　要：确定管路结构的疲劳极限对避免航空发动机燃油管路系统疲劳失效具有重要意义。本文分别开展了空管和充压管路(13.5MPa)的旋转弯曲疲劳试验,采用两路应变方法监测偏心旋转过程中由惯性引起的动态应力,基于Gerber模型对内压导致的非对称循环载荷进行了应力修正,获得了两种工况下管路疲劳失效形式的差异。通过升降法数据配对,确定了空管和充压管路的疲劳极限和标准差。在升降法数据的基础上,补充若干高应力水平下的疲劳试验,采用幂函数模型拟合了管路的S-N曲线。最后,利用概率统计分析方法对试验数据进行处理,获得了不同置信度和存活率下的疲劳极限。研究结果可为航发燃油管路应力严苛值设计提供参考。Determining the fatigue limit of tube is important for avoiding fatigue failure of aviation engine fuel structures.In this paper,the rotational bending fatigue tests were conducted on empty tubes and pressurized tubes(13.5MPa)respectively.Two strain gauges were used to monitor the dynamic stress caused by inertia during eccentric rotation.Based on the Gerber model,stress corrections were made to the asymmetric cyclic load caused by internal pressure,and the differences in the fatigue failure forms between the empty tubes and pressurized tubes were obtained.The fatigue limits and their standard deviations of the empty pipe and the pressurized pipe were determined through the data of up-down method.Based on the up-down method data,several fatigue tests under high stress levels are supplemented,and the S-N curve of the two type tubes were fitted by the power function model.Finally,the probability statistical analysis method is used to process the test data,and the fatigue limits under different confidence levels and survival rates were obtain.The research results provide the reference for the stress severity values of aircraft fuel tubes design.

关 键 词：旋转弯曲 升降法 S-N曲线 置信度 存活率 

分 类 号：V233.2[航空宇航科学与技术—航空宇航推进理论与工程]