航空发动机限寿件概率失效风险评估的等效应力转化  

Transformation method of equivalent stress for failure probability risk assessment on aero-engine life-limited parts

作　　者：丁水汀[1] 郭祎玮 李果[1,3] 周煜 DING Shui-ting;GUO Yi-wei;LI Guo;ZHOU Yu(National Key Laboratory of Science and Technology on Aero-engines Aero-thermodynamics,School of Energy and Power Engineering,Beihang University,Beijing 100191,China;AECC Commercial aircraft engine Co.,Ltd,Shanghai 200241,China;Institute for Aerospace Studies,University of Toronto,Toronto M3H5T6,Canada;School of Transportation Science and Engineering,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学能源与动力工程学院航空发动机气动热力国家级重点实验室,北京100191 [2]中国航发商用航空发动机有限责任公司,上海200241 [3]多伦多大学航空航天研究所 [4]北京航空航天大学交通科学与工程学院,北京100191

出　　处：《燃气涡轮试验与研究》2019年第1期1-7,19,共8页Gas Turbine Experiment and Research

基　　金：国家自然科学基金(51676009)

摘　　要：提出一种从整个飞行循环出发并基于全局的限寿件等效应力转化方法,将转化后的等效应力作为概率失效风险评估的输入条件,从而获得更为精确的失效风险结果。首先通过流固耦合数值模拟获得限寿件在整个飞行循环的瞬态应力,然后基于雨流计数法及线性累计损伤理论编制转换程序,将限寿件模型全部节点上的瞬态应力转化为等效应力,最后作为概率失效风险分析流程的输入条件确定寿命期内的概率失效风险。相同飞行循环条件下,与基于局部最大应力的转化方法相比,全局等效应力转化方法获得的失效风险更低。该方法的提出,为我国民机型号概率失效风险评估时作为关键输入数据应力的确定给出了定量参考,有力支撑了适航取证。An equivalent stress transformation method which based on aero-engine life-limited parts during the whole flight cycle is presented. In the method, equivalent stress is used as input conditions of failure probability risk assessment to obtain results that are more accurate. Firstly, the transient stress of life-limited parts during whole flight cycle is numerically simulated using fluid-structure interaction. A program which based on rain-flow method and linear damage accumulation theory is then applied to transfer the transient stress of nodes of life-limited parts into equivalent stress. Finally, the equivalent stress is used as input for probability risk assessment to determine failure probability risk in certain life period. Under the same flight cycle conditions, the failure risk obtained by the global transformation method of equivalent stress decreased compared with the results from the transformation method based on local maximum stress.These results can support the airworthiness forensics of aero-engine. This method can provide quantitative reference for critical input data like stress to support airworthiness certification when civil engine is under failure probability probabilistic risk assessment.

关 键 词：航空发动机 限寿件 适航取证 概率失效风险评估 流固耦合 全局应力转化方法 雨流计数法 线性累计损伤理论 

分 类 号：V232.3[航空宇航科学与技术—航空宇航推进理论与工程]