下穿U型道路在行驶车辆作用下的动力响应

为了解下穿U型道路在车辆荷载作用下的动力特性,通过对车辆、下穿U型道路振动系统的分析,将车-路耦合振动问题分解成两个独立的运动体系,即车辆振动子系统和道路振动子系统．利用车轮和路面的位移协调方程来考虑车路的接触,在空间整体车辆模型振动微分方程推导的基础上,考虑路面不平度的三维空间分布,对路面不平度非一致激励下U型道路的动力响应进行研究．结果表明,当路面平顺时,车-路耦合作用力波动很小;随着路况的变差,车-路耦合作用力迅速增大;在路面不平度的非一致激励下,左右轮作用力存在明显差异．车辆行驶速度对动载系数的影响较小,路面不平度对动载系数的影响较大．路况较差时,应考虑车辆荷载的冲击效应．

Dynamic responses of U-type road under moving vehicles

To analyze the dynamic characteristics of U-type road under moving vehicles, the coupled vibration problem is decomposed into two independent motion system, i.e. vehicle vibration subsystem and road vibration subsystem. The displacement coordination equation of wheel and pavement is used to consider the contact of vehicle and road. Based on the formula derivation of vehicle vibration differential equation, the dynamic responses of U-type road is analyzed and studied with the 3-D spatial distribution of road surface roughness considered. The results show that the fluctuation of vehicle-road coupling force is small when the road surface is smooth. The vehicle-road coupling force increases rapidly with the deterioration of road conditions. The forces of left wheel and right wheel is different under the non-uniform excitation of road surface roughness. Vehicle speed has little effect on the dynamic load coefficient comparing with road surface roughness. The impact of vehicle load should be considered under poor road conditions.