基于台架试验的轿车后扭梁悬架疲劳仿真研究

Fatigue simulation of twist beam based on the bench experiment

后扭梁悬架因其结构简单、成本较低且能满足一般的汽车动力学、运动学要求而被广泛应用于中低级轿车中。但由于后扭梁悬架既要保证足够的强度,以承受后轴的各种载荷,同时又要能提供合适的扭转刚度,以保证整车的侧倾刚度,导致后扭梁的受力比较复杂,高应力区域及危险区域也比较多。首先建立模拟后扭梁悬架台架试验的有限元分析模型,而后计算得到应力集中位置,并模拟后扭梁悬架台架试验条件下的疲劳载荷,借助于疲劳寿命分析软件估算后扭梁悬架各部分的损伤情况。经与台架试验结果的对比,所得试验数据与计算结果基本一致,表明基于有限元技术的后扭梁悬架疲劳寿命预测的可行性。最后分析后扭梁悬架前端刃口处开裂的原因,采用应力转移的思想,优化改进后扭梁悬架的局部结构。

Because of the simple structure and low cost,the twist beam has been widely used in the field of economy cars. Meanwhile,the structure of the twist beam can satisfied dynamics amt kinematics needs of the usual cars. However,it is necessary to ensure the sufficient strength to withstand the load of the rear axle. It is also neeessary to provide a suitable torsional rigidity to ensu,＇e the roll stiffness of the vehicle. The above situations leading to the twist beam suffer in a complicated force condition,and there are more stress intensity and hazardous areas. Used finite element method to simulate the bench experiment of the twist beam ,and then found out the strength intensity areas. With the help of the fatigue software,the damage of the twist beam could be calculated in the condition of the fatigue loads. Compared with the experiment results, it could be found that the simulation coincitied with the bench test results. And it could be concluded that based on the finite element method,it is possible to predict the fatigue life of the twist beam. In the end, the reason of the crack appearance in the front edge of the twist beam was found, based on the stress transfer, the optimized structure of the twist beam was proposed.