横风作用时间对高速客车直线运行安全性的影响

基于车辆/轨道耦合动力学原理,建立了横风作用下的车辆/轨道耦合动力学模型。模型中,车辆系统采用两系悬挂共35个自由度的多刚体动力学模型。轨道系统采用3层连续弹性离散点支承模型。用赫兹接触理论计算轮轨法向力,用沈氏理论计算轮轨滚动接触蠕滑力,并用显式积分法求解系统运动方程。横风由作用在车体中心的气动升力、侧力和倾覆力矩来模拟。通过数值计算,得到了横风作用下高速客车直线运行的系统动态响应,分析了不同横风作用时间对运行安全性的影响。结果显示,随着横风作用时间的增长,车辆脱轨系数、轮重减载率乃至倾覆系数迅速增大,车辆运行安全性不断降低。

Effects of Cross-wind Acting Time on the Safety of the High-speed Passenger Cars on Straight Line

In order to investigate the effect of cross - wind on railway vehicle derailment, the model of vehicle/track coupling dynamic under cross - wind is established. In the model, the vehicle is modelled as a full dynamic rigid multi - body model and a double suspension system, and the total degrees of freedom of the vehicle model are 35. The tracks are assumed to be a three - layer model resting on the continuous discrete sleepers. The normal forces of the wheels/rails are calculated using Hertzian contact theory and their creep forces are determined with the nonlinear creep theory by Shen et al. Lift forces, lateral forces and rolling moment on the central of high - speed vehicle are investigated to study the effects of cross - wind on vehicle. The motion equations of vehicle/track coupling system were solved with new explicit integration method. The dynamic response of cross - wind on high - speed passenger cars on straight line is calculated, and the effect of different cross - wind acting time on the safety of high - speed passenger cars is analyzed. With the increasing of cross- wind acting time, the derailment coefficients, the rate of the wheel load reduction and the rate of overturning increase quickly and the safety of vehicle is reduced.