直升机铝合金结构冲击凹坑缺陷深度统计及对应的疲劳性能研究  

STUDY ON FLAW DEPTH STATISTICS AND CORRESPONDING FATIGUE LIFE OF HELICOPTER ALUMINIUM ALLOY STRUCTURE

作　　者：倪阳[1] 周储伟[1] 喻溅鉴[2] 邹静[2] NI Yang;ZHOU ChuWei;YU JianJian;ZOU Jing(State Key Laboratory of Mechanics and Control of Mechanical Structures,College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;China Helicopter Research and Development Institute,Jingdezhen 333001,China)

机构地区：[1]南京航空航天大学航空学院机械结构力学及控制国家重点实验室,南京210016 [2]中国直升机设计研究所,景德镇333001

出　　处：《机械强度》2020年第4期941-946,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金项目(11272147);机械结构力学及控制国家重点实验室基金(0214G02);江苏高校优势学科建设工程资助。

摘　　要：直升机金属动部件的表面缺陷是其重要的疲劳破坏源。首先收集并统计分析了直升机铝合金关键动部件表面冲击凹坑缺陷的深度数据,结果发现其深度尺寸服从正态分布,并以90%的缺陷尺寸覆盖率为依据确定了冲击凹坑缺陷的标准尺寸。采用有限元方法结合连续损伤力学理论对一种航空常用铝合金材料(2A12)的冲击凹坑形成和疲劳起裂寿命进行了研究,并通过疲劳试验结果验证了方法的合理性。研究表明合理的冲击凹坑缺陷疲劳寿命分析必须考虑缺陷局部的残余应力和塑性应变的影响。Surface defect is the main fatigue failure source of helicopter metal dynamic components.Depth data of impact pit defects on surface of aluminum alloy critical dynamic parts of helicopter were collected,and statistical analysis was conducted.Statistic results show that the depth of impact pits obey the exponential distribution,and a standard size is confirmed according to the size coverage of 90%.The impact pit formation and fatigue crack initiation life of aluminum alloy(2 A12)commonly used in aviation were investigated using finite element method combined with continuum damage mechanics theory,and the rationality of the method was validated through fatigue test results.The study shows that a rational fatigue analysis of impact pit defect must take the local residual stress and plastic strain into account.

关 键 词：缺陷统计 疲劳寿命 冲击凹坑 有限元方法 连续损伤力学 

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]