悬架橡胶衬套对乘坐舒适性影响的双工况分析

Double Scenarios Analysis for Impact of Suspension Rubber Bushings on Ride Comfort

采用相对坐标法,输入试验获取的悬架螺旋弹簧及橡胶衬套部分参数特性曲线,在SIMPACK多体系统中建立某乘用车有、无橡胶衬套的多体整车模型;参考平顺性道路试验法规,对多体整车模型进行离线时间积分,获取座椅支撑面处三轴向的加速度时间历程,并利用MATLAB编制程序计算总加权加速度均方根值,参照IS02631中总加权加速度均方根值与人体感受之间的关系,比较发现该值在有橡胶衬套情况下较小,说明橡胶衬套对人体乘坐舒适性确有影响;再在两种设定工况下进行积分计算,发现橡胶衬套能提高乘坐舒适性,但在同路况不同车速下,有悬架橡胶衬套的整车模型对x,y轴向加权加速度均方根值的影响比对z轴向加权加速度均方根值影响大,同时车速的变化对总加权加速度均方根值的影响比路况变差对该值的影响大.

Based on relative coordinates, in SIMPACK system, multi-body car models with and without bushings were built by inputting some parameters of spring and rubber bushings from experiments. Ac- cording to some relevant test regulations of ride comfort, off-line time integrations were performed to get the acceleration-time histories of the seat surface in x/y/z-axis. A special MATLAB program was com- piled to calculate the value of total weighted RMS acceleration by calling the above histories, the value of the car model with bushings was smaller than that of the car model without bushings by referencing sub- jective reactions to total weighted RMS acceleration （ISO2631）, thus demonstrating that the rubber bush- ings did impact ride comfort. Double scenarios were set up, and time integrations were performed again to get the acceleration-time histories of the seat surface in x/y/z-axis. It was found that the rubber bushings improved ride comfort, but for the second scenario, the relative tolerances of x/y-axis weighted RMS ac- celeration between the car models with and without bushings were greater than those of z-axis weighted RMS acceleration. In addition, the influence of change in driving speed on the value of total weighted RMS acceleration was more obvious than the change in road roughness.