基于连续损伤力学的铝合金冲击局部损伤及后继疲劳寿命  

Impact Local Damage and Consequent Fatigue Life of Aluminum Alloy Using Continuum Damage Mechanics

作　　者：倪阳[1] 周储伟[1] 喻溅鉴[2] 邹静[2] NI Yang;ZHOU Chuwei;YU Jianjian;ZOU Jing(College of Aerospace Engineering,Nanjing University of Aeronautics & 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,南京210016 [2]中国直升机设计研究所,景德镇333001

出　　处：《南京航空航天大学学报》2019年第1期63-68,共6页Journal of Nanjing University of Aeronautics & Astronautics

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

摘　　要：基于连续损伤力学理论,对2A12铝合金冲击局部损伤及后继疲劳寿命进行了研究。首先采用有限元方法模拟了冲击过程,获得冲击凹坑局部的残余应力场与塑性应变场;然后根据残余应力状态选取疲劳破坏的危险点,通过Lermaitre塑性损伤模型得到危险点的初始损伤;最后根据修正的Chaboche疲劳损伤模型估算疲劳寿命。通过与相关的试验结果进行对比验证,表明连续损伤力学结合有限元分析方法可有效评估金属结构冲击损伤及后继疲劳寿命。Based on the continuum damage mechanics,the impact local damage and consequent fatigue life of 2A12 aluminum alloy are investigated. Firstly,finite element simulation of impact is conducted to obtain the local residual stress and plastic strain fields around the impact pit. Then the dangerous points are selected according to the residual stress state,and the initial damages are obtained based on the Lemaitre’s plastic damage model. Finally,the fatigue life of the impacted specimen is calculated using the modified Chaboche’s fatigue damage model. Compared with experimental data,the combination of continuum damage mechanics and finite element method(FEM)is proven feasible in evaluating the impact damage and consequent fatigue life of metal materials or structures.

关 键 词：疲劳寿命 冲击凹坑 残余应力 有限元模拟 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]