某乘用车悬架控制臂早期断裂原因分析及改进

Analysis of early fracture of suspension control arms of a passenger car and its improvement

针对某乘用车副车架在疲劳台架试验中控制臂早期断裂问题,采用有限元法对控制臂进行静力分析且找出了结构薄弱位置,利用应力应变电测试验验证了控制臂有限元模型的正确性.从焊接结构出发,分析了控制臂早期断裂的原因,并以此为依据提出了一种改进方案.根据改进方案试制控制臂样件并对其进行电测试验,结果表明:改进后控制臂焊接接头局部应力下降明显;通过疲劳台架试验证明,改进方案解决了控制臂早期断裂问题.

Aimed at the control arms＇ early fatigue fracture in a passenger car＇s sub-frame fatigue bench test,a method of linear static analysis was applied to locate the weak points of the structure of control arms. Then,the accuracy of the finite element model was verified by a stress-strain test. According to the welding structure of the control arm,the reasons of the control arms＇ early fractures were analyzed and the solution was put forward. Based on the improved scheme,samples of the control arm were made,on which stress-strain test was conducted. The test shows that the local stress of the welding joints of the control arms decreases significantly. Finally,the fatigue test shows that improved scheme solves the problem of the early fracture of control arm.