车-桥-线竖平面振动及其能量转化机制精细建模

建立了考虑车-桥(线)纵向振动及其能量相互转化机制的竖平面内精细耦合运动方程.将车-桥(线)视为一个整体系统,车辆各剐体的纵向运动均作为独立的自由度,考虑到车-桥(线)纵向振动及其能量相互转化机制,车辆驱动或制动作用采用轮轨间的纵向相互作用力和轮对作用力矩模拟,桥梁、线路结构采用梁单元离散,线路与桥梁之间的钢轨基础采用竖向和纵向的均布弹簧阻尼连接,建立了竖平面内精细耦合运动方程,它可合理模拟车桥(线)间能量相互转化的过程.简支梁桥算例表明:车辆在桥上无驱动或制动运行过程中,不考虑轨道结构时车速先增加后减小,而考虑轨道结构时车速只有减小的趋势,轮对还发生了高频的纵向振动,且车体和轮对的纵向振动对轨道竖向不平顺较为敏感;此外,考虑轮轨滚动碾压作用和能量转化机制时,钢轨加速度响应略偏大.本文研究可为实际车辆动态变速运行的模拟和更精细空间耦合模型的建立提供研究基础.

The model of train-bridge-track interaction and energy transformation in vertical plane

The refined motion equation of longitudinal vibration of the train-bridge-track system in vertical plane considering the longitudinal vibration of the vehicle and energy conversion is established in this paper.Taking the train-bridge/track as a whole system,and the longitudinal vibration of the vehicle rigid bodies as independent degree of freedom,and the driving or braking function is simulated by wheel/rail longitudinal force or wheel set moment,and the bridge and track are discretized by beam elements while the rail foundation connecting bridge and track are simulated by equably distributed spring dampers,the refined motion equation in vertical plane considering the longitudinal vibration of the vehicle and energy conversion is developed,which can model the energy conversion between the train and bridge reasonably.Numerical simply supported beam examples demonstrate that:without considering track structure,the velocity of vehicles running on the bridge without driving or braking operation process first increases and then decreases,otherwise it decreases and the wheel sets outputs high frequency longitudinal vibration.The longitudinal vibration of the vehicle body and wheel sets is sensitive to track irregularity.In addition,rail acceleration response is slightly higher compared with the traditional model.This study can provide research foundation for the simulation of dynamic shift operation of actual vehicle and the developed of more refined space coupling model.