基于实测载荷谱的车架结构仿真优化方法及应用

Simulation and optimization method of vehicle frame structure based on measured load spectrum and its application

为解决某型车辆在试验过程中出现的车架开裂问题,提出一种基于实测试验载荷谱与数值仿真分析相结合的车架结构优化方法,并在试验中得到应用验证。主要内容包括:建立集六分力传感器、加速度传感器、位移传感器、应变传感器为一体的多通道数据采集系统,获取实际行驶试验底盘载荷谱原始数据,利用零点漂移、去趋势项、去噪等信号处理技术得出载荷谱分析数据,采用定性与定量相结合的方法分析车架结构开裂的故障原因。建立车架有限元仿真模型,基于试验载荷谱分析数据,在不影响整体结构的基础上提出优化方案,计算比较优化前后的车架结构在典型受力工况下的力学特性,保证优化后受力满足要求。利用RPC迭代技术,基于实测载荷谱数据迭代计算得到响应驱动信号,应用于整车道路模拟试验台,开展台架试验,验证车架设计优化的有效性。最后对优化后的车架进行完整的可靠性行驶试验,结果表明:优化后的车架未发生故障且满足可靠性指标。该研究以解决实际问题为出发点,为整车高可靠性设计技术提供了有效、可行的方法。

Here,to solve the problem of frame cracking of a certain type vehicle during tests,an optimization method of vehicle frame structure based on combination of measured test load spectrum and numerical simulation analysis was proposed,and applied in tests for verification.Firstly,a multi-channel data acquisition system integrating 6 component force sensors,acceleration ones,displacement ones and strain ones was established to obtain the original data of chassis load spectrum in actual driving tests.Load spectrum analysis data was obtained by using signal processing techniques of zero drift,trend term removal and noise removal.Fault causes of frame structure cracking were analyzed by combining qualitative and quantitative methods.Secondly,the finite element simulation model of vehicle frame was established.Based on the test load spectrum analysis data,the optimization scheme was proposed on basis of not affecting overall structure.Mechanical characteristics of the frame before and after optimization under typical stress conditions were calculated and compared to ensure stress after optimization meeting requirements.Thirdly,RPC iterative technology was used to iteratively calculateresponse drive signals based on measured load spectrum data,and drive signals were applied inthe overall vehicle road simulation test platformfor bench tests to verify the effectiveness of frame design optimization.Finally,complete reliability driving testswere conducted for the optimized frame.The results showed that the optimized vehicle frame has no fault and satisfies reliability indexes;the study can take solving practical problems as the starting point,and provide an effective and feasible method for high reliability design technology of whole vehicle.