基于混合路面加载的车身疲劳载荷预测

Vehicle Body Fatigue Load Prediction Based on Hybrid Road Loads

采集车辆在试验场耐久路面行驶的轮心道路载荷谱、关键部件载荷谱以及其它响应信号。以悬架位移和轴头垂向加速度为目标,迭代反求获得等效路形。结合其余五分量道路载荷形成混合路面,驱动整车多体模型仿真分解得到车身载荷谱。分析结果表明,混合路面加载预测的车身载荷与实测十分吻合,精度较高。改型车和原车型如果具有相近的簧下质量和轮胎,则两者的等效路形一致,所以原车型载荷可以沿用到改型车,这样更方便进行其车身的疲劳寿命评估。

The road load datacollected at the wheel center,load spectrums of key components and other response signals of the vehicle were measured under the condition of driving on the durability roads of proving ground.Taking the suspension displacement and spindle acceleration as targets,the effect road profile(ERP)was obtained through iterative back-calculation.The hybrid road load was formed by integrating the ERP and other five load components.The whole vehicle multi-dynamic model was simulated and the body load spectrum was obtained subsequently.The analytical results show the predicted car body load by using the hybrid road loads are consistent with the measurement results quite well.The modified vehicle shares the same ERP as the original one if both have similar unspring mass and tire.In other words,the original model vehicle load can be applied to the modified one,which makes it more convenient to evaluate the fatigue life of the vehicle body.