车辆-轨道垂向耦合系统空间频域传递特性研究

Spatial Frequency Domain Transfer Characteristics of Vertical Vehicle-track Coupling System

基于车辆-有砟和无砟轨道垂向耦合系统模型,建立由轮轨垂向激励到车辆和轨道部件位移和加速度等状态变量的解析形式的瞬态空间频域传递函数。在此基础上,研究不同轨道系统下,车辆各部件加速度频域传递特性以及轨下各部件间作用力频域传递特性的异同点。给出为准确获得系统频域传递特征,有砟轨道系统下钢轨模态数与支撑轨枕数的合理比例关系。对比匀速和变速过程中构架加速度空间幅频传递特性的差异。研究结果表明,速度为250~350 km/h条件下,车辆部件振动加速度的传递特征峰值区主要包括空间频率为0.4~1 (1/m)和6~8.5 (1/m)的两段。有砟系统下,轮轨力传递特性峰值主要集中在0.8~1.6(1/m)的频段;无砟系统下,轮轨力传递特性峰值包括空间频率为0.7~1.2 (1/m)和4~8 (1/m)的两段。随运行里程的增加,变速工况下传递特性,各条带向空间频率减小方向移动,且条带频率越高,这种移动的趋势越大。

Based on vertical vehicle-track coupling system,both considering ballast track and non-ballast track model,the transient spatial frequency transfer function from wheel-rail irregularity to state variables of the various components of the vehicle and track system is established.With the transient spatial transfer function,under different track system,the similarity and difference of the acceleration amplitude frequency transmission characteristics of the vehicle components and the interaction between the components of track system are studied.The ratio between the number of sleepers and the number of track modal is obtained in order to get a more precise transfer characteristics of the vehicle components.Under different operating conditions such as uniform and variable speed process,the differences of the transfer characteristics of vehicle system components are analyzed.The results show that,with the speed of 250-350 km/h,the main energy transfer range is 0.4-1.2(1/m)and 6-8.5(1/m).Under ballast track system,the transmission characteristic’s peak of the wheel-rail force is at the frequency range of 0.8-1.6(1/m).Under ballastless track system,the peak value of wheel-rail force transfer characteristics includes t two spatial frequency ranges of 0.7-1.2(1/m)and 4-8(1/m).With the increase of distance,the strip of the transmission characteristics are moving to the direction with a space frequency decreasing,and the higher the frequency range is,the larger the moving trend is.