本文通过具有随机结构参数的四分之一车辆模型研究了具有不确定性结构参数的车辆在受到来自道路的随机激励作用下的振动响应问题。文中将簧上质量、簧下质量、悬挂阻尼、悬挂刚度以及轮胎刚度均认为是随机变量。将路面的不平整引起的对车辆的激励看作高斯随机过程并通过简单指数功率谱密度来建立力学模型。利用蒙特卡洛方法得出了车辆的固有频率和模态振型的均值、标准差以及变异系数。利用随机变量函数矩方法在频域中建立了车辆的随机响应的均方值的数字特征的计算表达式。通过工程算例表明了车辆结构参数的随机性对其动力响应的影响。本文所做的工作可拓展应用于车辆结构参数的灵敏度分析和动力优化设计。

This paper present the investigation on the dynamic analysis of cars with uncertain parameter under random road input excitations using a quarter-car model. The sprung mass, unsprung mass, suspension damping, suspension and tyre stiffness are considered as random variables. The road irregularity is considered a Gaussian random process and modeled by means of a simple exponential power spectral density. The mean value, standard deviation and variation coefficient of the vehicle’s natural frequencies and mode shapes are obtained by using the Monte-Carlo simulation method. The computational expressions for the numerical characteristics of the mean square value of vehicle’s random response in the frequency domain are developed by means of the random variable’s functional moment method. The effects of the randomness of the vehicle’s parameters on the vehicle’s dynamic response are investigated. The method proposed in this paper can be further developed for sensitivity analysis and dynamically optimal design of vehicle parameters.