某乘用车后轴在疲劳台架试验过程中扭杆出现早期断裂,应用有限元法对后轴进行静强度分析,找出结构薄弱环节,并利用应力应变电测试验验证有限元分析方案,再从应变幅与疲劳寿命关系的角度分析扭杆断裂的原因,在此两种分析基础上提出改进方案,经疲劳台架试验,证明改进后的设计方案成功解决了扭杆早期断裂的问题。 The torsion bar early fracture of the rear axle of a passenger car during the fatigue test was analyzed. The static strength of the rear axle was analyzed by finite element method to find the structural weak links. The finite element analysis program was verified by the stress-strain test , And then from the relationship between strain amplitude and fatigue life analysis of the reasons for the torsion bar rupture, in these two analysis based on the proposed program of improvement, the fatigue test bench to prove that the improved design successfully solved the problem of torsion bar early rupture .