汽车底盘结构件焊缝承载评价方法研究

以汽车底盘结构件(后桥与副车架)为研究对象,对其焊缝承载评价方法进行了研究.选取后桥的悬架臂和衬套管为模拟件,采用热弹塑性有限元法对模拟件的焊接残余应力进行了预测,设计了模拟件的拉伸试验.将模拟件的焊接残余应力和拉伸载荷合成计算,得到模拟件的合成应力,计算结果与拉伸试验结果基本一致.利用ANSYS软件的批处理命令获得焊缝与母材交界面外围轮廓线上的合成应力,并取外围轮廓线上取最大应力值σmax={σx,σy,σx},在此基础上建立了焊缝破坏判 据,并确定了评判焊缝承载性能的安全系数N及其范围.将此焊缝承载评价方法应用于后桥和副车架,并预测其焊缝危险位置,结果表明,此方法可以准确预测出后桥与副车架的焊缝危险位置.

Study on weld load-carrying evaluation method of car's chassis

In this article weld load-carrying evaluation method for car’s chassis(rear axle and sub-frame) is discussed.Based on rear suspension arm and bushing,welding residual stress is simulated by using thermal elastic-plastic finite element method,and the tensile test is design.Welding residual stress and working stress is coupled,and get compound stress field,comparisons of calculated and tensile test results show good agreement.We get compound stress on the contour line outside weld and mother material interface,and obtain maximum stress value σmax={σx,σy,σz},and then weld damage criterion is built,safety factor N of appraising weld load-carrying properties is established.Weld load-carrying evaluation method is applied to rear axle and sub-frame in order to predict weld dangerous position,and it shows that the method can accurately predict weld dangerous position of rear axle and sub-frame.