参数不确定性车辆的复合随机振动分析

Compound Random Vibration Analysis of Vehicles with Uncertain Parameters

提出了虚拟激励-快速摄动法来研究路面随机激励和不确定车辆系统的复合随机振动问题。采用虚拟激励法将随机激励转化为简谐激励,推导了车辆振动响应功率谱密度的表达式,然后基于快速摄动法计算垂向加速度均方根值的变异系数,由响应的变异反映复合随机对车辆结构振动响应的影响。对参数不确定1/4车辆模型的仿真分析表明:当悬架结构参数和轮胎刚度变异系数为0.1时,垂向加速度均方根值的变异达到18.81%,与蒙特卡洛法相比,本文方法计算速度显著提高,且误差在5%内。

Aiming at the random vibration of vehicles with uncertain system parameters under random excitations, random vibration response of a quarter vehicle model is analyzed based on the pseudo-excitation and rapid perturbation method. The pseudo-excitation method is used to transform the random excitation into a simple harmonic excitation, and the expression of power spectral density of the vehicle vibration response is derived. Then, the variation coefficient of the vehicle body acceleration response is calculated based on the fast perturbation method. The numerical example of vibration analysis shows that when variation coefficient of the body structure parameters and the tire stiffness are 0.1, the variation coefficient of the vehicle body acceleration is up to 18.81%. Compared with the Monte Carlo method, it shows that computational efficiency is improved greatly with the methods of this paper, and the error is less than 5%.