基于随机载荷的白车身焊点疲劳寿命预测  

Fatigue Life Prediction for the Spot Welds of Body-in-white Based on Random Loadings

作　　者：龙海强[1,2] 胡玉梅[1,2] 刘波 金晓清[1,2] 朱浩[1,2] 

机构地区：[1]重庆大学,机械传动国家重点实验室,重庆400044 [2]重庆大学汽车工程学院,重庆400044 [3]长安汽车工程研究院,重庆401120

出　　处：《汽车工程》2016年第8期1006-1010,共5页Automotive Engineering

基　　金：“十二五”国家科技支撑计划(2011BAG03B01);重庆市杰出青年项目(cstc2014jcyjjq50002)资助

摘　　要：针对车辆开发过程试车场试验中的焊点疲劳失效这一普遍现象,根据道路试验要求采集车辆耐久试验路面载荷谱,并通过虚拟迭代的方法获得了某车型车身与底盘19个连接点的三向力和力矩载荷的时间历程。建立白车身与焊点有限元模型,应用Nastran惯性释放法计算各连接点单位载荷激励下焊点和周边钣件的应力分布。以虚拟迭代的载荷谱为激励,完成焊点疲劳分析与累积损伤叠加,预测了设计焊点的潜在风险并通过局部增加焊点和优化焊点布置提升了焊点的疲劳寿命。In view of the common phenomenon of fatigue failure of spot welds occurred in the proving ground test during vehicle development process,firstly the road load spectra in vehicle durability test are collected according to road test requirements and the time histories of force and moment loadings in three directions of 19 connection points on the body and chassis of a vehicle are obtained by using virtual iteration. Then a finite element models for body- in-white with welding spots is built, and the stress distributions in the spot welds of connecting points and their surrounding panels are calculated by applying inertia relief method in Nastran. Finally with the loading spectra obtained by virtual iteration as excitations,the fatigue analysis and accumulated damage superimposition are performed,the potential risks of spot welds designed are predicted and the fatigue lives of spot welds are enhanced by locally adding spot welds and optimizing spot weld layout.

关 键 词：白车身 焊点 疲劳寿命 载荷谱 虚拟迭代 

分 类 号：U463.82[机械工程—车辆工程]