无砟轨道垂向高频振动响应分析

Vertical high frequency vibration response analysis of ballastless track

为了分析不平顺条件下无砟轨道的高频振动特性及声辐射特性,建立了高速铁路无砟轨道车辆-轨道垂向耦合动力学模型,在轮轨表面粗糙度激励下考虑接触滤波,模拟出了轮轨垂向高频振动相互作用力,并将此力作用在按我国实际轨道结构建立的三维实体有限元模型上,仿真模拟轨道系统在随机荷载作用下的高频振动特性,得到了钢轨轨头、轨腰、轨底3处的振动响应与轨道板同一截面离钢轨不同距离的3处振动响应和竖向振动加速度级谱。结果表明:钢轨振动响应中轨头处振动响应最大,轨道板振动响应中距离钢轨越近响应也越大;在计算频域内轨道系统的高频振动主要以钢轨的振动为主,钢轨高振幅的振动主要集中在0～3 000 Hz,而轨道板的高振幅振动就主要集中在0～1 000 Hz,这为以后采用三维轨道结构面上的振动响应结果作为速度边界条件,利用声学边界元法计算轨道的声辐射奠定了基础。

In order to analyze the high frequency dynamical and the sound radiation characteristics of unballasted track under an irregularity condition,the paper proposed a vehicle-track vertical coupled model of high-speed railway.Under the incentive of surface roughness and considering contact filtering,the high frequency vertical load between rail and wheels can be calculated.Applying the load on the three dimensional finite element model,based on the rail structure of actual conditions in our country,the high-frequency vibration features of track system under the influence of random vibration loads can be numerically modeled,and the vibration response at the head,waist and base of the rail,the vibration response and vertical vibration acceleration spectrum level of three different sections parallel to the rail plate were calculated.The results show that the biggest vibration response of the rail appears at the rail head while that of the rail plate turn up at the one closer to the rail.The dominate high-frequency vibration of the rail system within the frequency included in the calculation is vibration of rail of which the high amplitude range is 0~3 000 Hz,while,as for the rail plate,the range mainly is 0~1 000 Hz.The domain provided a foundation for using the calculation result of vibration response on the 3D rail structure as speed boundary and calculating orbit sound radiation by acoustic boundary method.