飞机结构耐久性严重谱下疲劳分散系数研究  

STUDY ON FATIGUE SCATTER FACTOR OF AIRCRAFT STRUCTURE UNDER DURABILITY SEVERE LOAD SPECTRUM

作　　者：王勇军 李唐 兑红娜 WANG YongJun;LI Tang;DUI HongNa(Chengdu Aircraft Design and Research Institute,Chengdu 610091,China)

机构地区：[1]成都飞机设计研究所,成都610091

出　　处：《机械强度》2021年第4期955-959,共5页Journal of Mechanical Strength

摘　　要：疲劳分散系数是使用载荷谱下的飞机结构寿命可靠性指标,用于描述疲劳分析和试验结果的可靠度。军用飞机结构强度规范(GJB67.6-2008)规定,当采用平均谱进行耐久性分析时,分散系数一般取4,对应99.9%可靠度;而当采用严重谱进行分析时,分散系数在2~4之间,但具体值并未明确。参考了大量的相关资料,在载荷谱造成的疲劳损伤与结构临界损伤值均服从对数正态分布前提下,对疲劳分散系数进行理论推导,并结合疲劳试验寿命分散性研究结果,明确了耐久性严重谱下结构寿命的疲劳分散系数,为国内将耐久性严重谱应用于军机结构疲劳设计和全尺寸疲劳试验打下了基础。Fatigue scatter factor is the reliability index of aircraft structure life,which is used to describe the reliability of analysis and test results.When average spectrum is used for durability analysis,the scatter factor is generally set as 4,corresponding to 99.9%reliability.In the case of using severe spectrum,the scatter factor is between 2 and 4,but the specific value is not clear in aircraft strength specification.By referring to a larger number of relevant research and according to the results of scatter study on component-level fatigue tests,the fatigue scatter factor of aircraft structures under severe spectrum was clarified,which lays a foundation for the application of durability severe spectrum in fatigue design and full-scale test of military aircraft.

关 键 词：疲劳分散系数 严重谱 可靠性 疲劳寿命 全尺寸疲劳试验 

分 类 号：V215.2[航空宇航科学与技术—航空宇航推进理论与工程]