【摘要】 为研究轨道交通车辆经过高架桥时的动态特性,以弹性支承块式无砟轨道为例,基于车辆-轨道耦合动力学理论,建立了车辆-轨道-桥梁耦合系统的竖向振动矩阵方程,利用MATLAB软件编写了计算程序。数值算例验证了计算程序的可靠性。通过改变系统参数,探索了轨道不平顺、车辆速度和轨道结构竖向刚度对系统竖向振动响应的影响。结果表明:轨道振动频率分布在0~500 Hz范围内,以20 Hz以内的低频振动为主;桥梁振动频率分布在0~200Hz范围内,以一阶竖向弯曲振动为主;轨道不平顺所产生的轮轨高频冲击力可达轴重的3倍,是车辆-轨道-桥梁耦合系统重要激励源之一;轮轨力和轨道加速度响应对车速的变化敏感,车辆-轨道-桥梁耦合系统位移响应对车速的变化不敏感;扣件和支承块胶垫竖向刚度应根据设计要求在40~80 k N/mm之间进行合理匹配取值。更多还原

【Abstract】 To study the dynamic performance of elastic supporting block track when the train runs on the viaduct,ballastless track with elastic supporting block is taken as the example,and based on vehicle-track coupling dynamics theory,a matrix equotian for vehicle-track-bridge vertical coupling vibration is built and a programis designed on MATLAB software. A numerical example verifies the reliability of the program. By changing the systemparameters,the influences of vehicle speed,track vertical stiffness and track irregularity on the systemvertical vibration responses are investigated. Results showthat the frequency distributions of track and bridge are between 0 ~ 500 Hz,the main vibration frequencies of track are bellow20 Hz while the bridge is centered on first-order vertical bending vibration bwtween 0 ~ 200 Hz. Track irregularity is an important source of excitation to the system,and the impact force can reach to 3times bigger than of axle load due to the irregularity. Wheel / rail force and track acceleration responses are more sensitive to the change of vehicle speed than the displacement responses. So the vertical stiffness of rail fastener and block pad should match each other and be valued between 40 ~ 80 k N / mmaccording to the design requirements.更多还原