一系定位刚度对车辆系统一次蛇行的影响分析

Analysis of the Impact of Primary Suspension Stiffness on Vehicle Hunting Motions

车辆系统蛇行运动的2种典型形式是一次蛇行和二次蛇行,又被称为车体蛇行和转向架蛇行。当车辆发生一次蛇行时,车体左右晃动幅度较大,影响车辆运行的平稳性以及乘客乘坐的舒适度。文章利用SIMPACK软件建立了300km/h整车非线性动力学模型,仿真车体一次蛇行失稳情况;结合非线性振动系统的频率俘获原理,研究发现车体一次蛇行是由于在行车过程中转向架的蛇行频率被车体的蛇行频率俘获所引起的。通过改变车辆系统的一系定位刚度,从而改变同等运行速度下转向架的蛇行频率,避开了车体的频率俘获区间,可有效抑制一次蛇行,提高车辆运行稳定性。

There are two typical forms of hunting motions in vehicle systems,i.e.,primary and secondary hunting motions,also called vehicle and bogie hunting motions.When primary hunting occurs,the vehicle body shakes intensely from left to right,which affects the stability of the vehicle and the comfort of passengers.By using the SIMPACK software to set up the 300 km/h nonlinear dynamic model,the vehicle hunting instability was simulated.Combined with the principle of frequency capture in nonlinear vibration systems,it was found that primary hunting motions was caused by the hunting frequency of the bogie being captured by the vehicle’s hunting frequency.By changing the primary suspension stiffness,the bogie’s hunting frequency was changed at the same operating speed,avoiding the frequency capture zone of the vehicle,effectively suppressing the vehicle hunting motion and improving the vehicle stability.