基于位移反求加载法的高精度皮卡车架疲劳开发与验证

Fatigue Development with High-Precision and Verification for Pickup Truck Frame Using the Displacement-Based Inverse Load Estimation

车架是皮卡的重要总成,由于承受各种载荷冲击,所以容易产生开裂问题影响使用寿命。皮卡车架的疲劳预测选择了精度较高的基于位移反求加载法,结合试验场采集载荷谱数据与皮卡整车多体动力学模型,以相关性较高的整车内部响应信号(悬架位移信号、整车轴头Z向加速度信号、转向拉杆力标定信号)为目标信号,迭代反求整车等效位移激励信号,进而分解获取车架边界载荷谱,最后基于Miner线性累积损伤理论对皮卡车架进行疲劳分析、对标及优化,优化后的实车通过台架试验验证。

The frame is an important assembly of pickup trucks,and it is easy to produce cracking problems and affect the service life when subjected to various load impacts.For the fatigue prediction of the pickup truck frame,a high-precision displacement-based loading method was selected,which combined the load spectrum data collected on the test site and the multi-body dynamics model of the pickup truck.The suspension relative displacement signals,spindle vertical acceleration and steering rod force with high correlation were selected as the desired signals.Iteratively inversely find the vehicle equivalent displacement excitation signal,and then decompose to obtain the frame boundary load spectrum.Finally,the fatigue of the pickup truck frame was based on the Miner linear cumulative damage theory analysis,benchmarking and optimization.The optimized car passed the bench test verification.