基于载荷损伤分散的严重谱选取方法初探  

PRIMARY ANALYSIS ON THE SELECTION METHOD OF SEVERE LOAD SPECTRUM BASED ON THE FLEET LOAD DAMAGE VARIATION

作　　者：贺小帆[1] 刘家曦[2] 王强[1] 刘文珽[1] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191 [2]北京航天航空大学电子信息工程学院,北京100191

出　　处：《工程力学》2015年第7期32-37,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(11002009);中央高校基本科研业务费专项资金项目

摘　　要：在飞机结构设计定型阶段,要综合考虑结构的差异和载荷的分散性评定机群的安全寿命。美国空海军联合规范指南JSSG-2006、标准MIL-STD-1530C和我国国军标GJB67.6A-2008提出采用90%谱(严重谱)进行飞机结构耐久性分析和试验,但并未给出严重谱严重程度的选取准则。该文以机群载荷损伤分散描述机群载荷分散,初步探讨了载荷谱严重程度的选取方法。假定指定谱下的结构寿命和机群载荷损伤均服从对数正态分布,在综合载荷损伤和结构分散性的寿命分布基础上,分析了严重谱下的寿命可靠度。按机群安全寿命满足99.9%的可靠度要求,以载荷损伤覆盖概率描述载荷谱严重程度,给出了载荷谱严重程度的表示形式,并针对典型的飞机结构分散和载荷损伤分散性参数,给出了典型的载荷损伤覆盖概率取值。分析表明严重谱的严重程度与载荷损伤分散性和结构分散性均有关,基于损伤的90%严重谱可以保证机群内超过99%飞机的使用安全。In the design phase for an aircraft structure, the fleet safe life should be assessed by accounting for the variability both in the structure and in load spectra. A 90% load spectrum （severe spectrum） has been proposed for the durability analysis and testing in JSSG-2006, MIL-STD-1530C in USA and GJB67.6A-2008 in China. But there are some confused viewpoints on the severity of the severe spectrum. This paper discusses primarily the selection method of the severe load spectrum. Assuming the life and the load damage have the log-normal distributions, and using the probability to represent the load spectrum severity, the expression of the load spectrum severity is obtained. For certain structural and load spectra standard variations, the severe probability value is derived. The results show that the load spectrum severity is related to the load scatter and structural scatter, and that the 90% severe spectrum based on damage as given in this paper ensures approximately the safe requirement of fleet structures.

关 键 词：载荷谱 疲劳 严重谱 平均谱 飞机结构 安全寿命 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]