Response of vehicle suspension system has traditionally been studied under the assumption of stationary road excitation. However, road excitation becomes a non-stationary random input in the time domain when the vehicle travels at a varying speed. In this paper, we investigate the non-stationary response of vehicle suspension under random road excitation. Despite its importance and relevant applications, this problem has not been well addressed in the literature. The non-stationary random road excitations in the time domain are computed using a high precision Gaussian-Legendre integration method. The evolutionary spectral theory is then applied to evaluate the response in the time-frequency domain. Numerical results for a quarter-car model are presented and effects of vehicle acceleration and road roughness on the ride comfort, energy dissipation from the suspension, and time-variant half-power frequency band for the constant speed and various constant acceleration cases are examined. The consideration of energy dissipation provides new insights on the relationships between ride comfort and fuel consumption, which is important for designs of optimized energy-ride comfort suspension systems under non-stationary road excitations.

传统上研究车辆悬架系统的响应是在静止道路激励假设下进行的。然而，当车辆以变化的速度行驶时，道路激励成为时域中的非平稳随机输入。在本文中，我们研究了随机道路激励下车辆悬架的非平稳响应。尽管它的重要性和相关应用，这个问题在文献中还没有得到很好的解决。使用高精度 Gaussian-Legendre 积分方法计算时域中的非平稳随机道路激励。然后应用演化谱理论来评估时频域中的响应。给出了四分之一汽车模型的数值结果以及车辆加速度和路面粗糙度对乘坐舒适性的影响，检查了悬架的能量耗散，以及恒速和各种恒加速度情况下的时变半功率频带。能量耗散的考虑提供了关于乘坐舒适性和燃料消耗之间关系的新见解，这对于非平稳道路激励下优化的能量乘坐舒适悬挂系统的设计很重要。