交变载荷下铝合金冲击凹坑局部残余应力松弛的数值研究  

Numerical study on local residual stress relaxation at impact dent of aluminum alloy caused by cycle load

作　　者：周世友 周储伟[1] 倪阳[1] 郝建群 ZHOU Shi-you;ZHOU Chu-wei;NI Yang;HAO Jian-qun(Mechanical Structure Mechanics and Control National Key Laboratory,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学机械结构力学与控制国家重点实验室,江苏南京210016

出　　处：《世界有色金属》2018年第15期190-191,共2页World Nonferrous Metals

摘　　要：金属结构表面缺陷处的残余应力对于其疲劳寿命有很大影响。采用数值分析方法模拟了铝合金2A12冲击凹坑缺陷处残余应力的产生和在后继交变应力下的松弛,研究了交变应力最大(最小)值、平均应力、应力比等因素对残余应力松弛的影响。模拟结果发现残余应力松弛主要发生在第一次交变载荷内,并且残余应力随交变载荷最大(最小)值增加呈现指数下降,而凹坑底部残余应力松弛量随交变载荷平均值增加而增大,而凹坑边缘残余应力松弛量随平均值的绝对值增加而增加。Local residual stress at flaw on surface of metal structure has great impact on fatigue life.The generation of local residual stress and consequent relaxation caused by cycle load at impact dent are simulated using numerical method.The effects of maximum（or minimum）value of cycle load,average stress and stress ratio on residual stress relaxation are investigated.The simulation found that residual stress relaxation takes place mainly during the first cycle of fatigue load,and the residual stress decreases exponentially with the increase of maximum（or minimum）value of cycle load.The residual stresses relaxation at bottom and edge of impact dent increases with average value and absolute average value of cycle load,respectively.

关 键 词：残余应力松弛 冲击凹坑 铝合金2A12 有限元模拟 

分 类 号：TG668[金属学及工艺—金属切削加工及机床]