中文摘要：

在虚拟激励法的基础上，建立了人车路垂向动力学模型和道路虚拟输入模型，推导了车辆非匀速行驶的时一空频率关系，得到了车辆非平稳响应的瞬时功率谱，应用Mathematic语言编制了四分之一人车模型的仿真程序，以简化模型为例，考察了变速车辆行驶的平顺性．数值仿真结果表明，虚拟激励法用于求解车辆振动响应，尤其是用于非平稳随机输入下的车辆振动分析，简便快捷，省时省力，能很好地反映汽车乘坐舒适性．

英文摘要：

The vertical model of vehicle dynamics and the virtual model of road input were deduced in pseudo -excitation method. The correlation between time and spatial frequencies was derived. The transient Power Spectral Density（PSD） of vehicle in nonstationary random vibration was obtained. A system performance simulation program for 3 DOF＇s vehicle model was developed by using Mathematic language. As an illustrative example, the rood-induced random response of a man-car model was explored. As a result, it was highly efficient to solve the vibration problem of vehicle, especially to solve nonstationary random vibration of vehicle in pseudo-excitation method, and it was also easy to calculate in that method, It will be useful in the assessment of vehicle ride comfort.