利用计算机仿真技术预测车身零件疲劳寿命

为缩短新车开发周期、节约样本制造费用，本文提出了一种在计算机仿真环境中预测车身零件疲劳寿命的新方法。以某轻型客车为例，首先建立了该车的整体有限元模型。然后将采自试车场的典型路面谱作用于轮胎与路面 的接触点进行随机激励。不仅首次在计算机上模拟了汽车随机振动过程，而且得到了关键部位的加速度和动态应力响应及其相应的功率谱密度。最后，应用随机振动和疲劳累积损伤理论对仿真结果进行后处理，估算出该车在一定速度下连续行驶的疲劳寿命。其分析结果显示的危险部位与道路试验基本一致。

Fatigue Life Prediction of Car Body Parts Using Computer Simulation Technology

To shorten the development lead time of new style vehicle and to reduce the manufacturing cost of its prototype, a new simulation method, which predicts the fatigue life of all body parts by computer simulation, is presented. Based on a light bus structure, a full finite element model is constructed first. Then, a typical road surface spectrum, collected from a real proving ground, is applied on the contact points between tires and road. Not only the random vibration process of the bus is simulated for the first time on a computer, but the acceleration and dynamic stress response at key areas and corresponding power spectrum densities have also been acquired. Finally, by means of the theories of random vibration and fatigue cumulative damage, above simulation results are post processed and the fatigue life of the bus body is estimated under a condition of continuous running at a given speed. The analysis results coincide with the road test quite well.