不同减振扣件的轨道结构横向振动测试与分析

Testing and Analysis of Lateral Vibration of Metro Tracks with Different Rail Baseplates

轨道结构的固有特性不因车辆系统及列车运营状态的变化而变化,可通过轨道的振动动态频响测试来辨识系统的传递特性和特征参数。基于国内某地铁正常运行的350 m小半径曲线线路,测试双层非线性减振扣件、III型轨道减振器扣件及DTVI2减振扣件等3种轨道结构线路在正常列车运营条件下钢轨动态振动响应及对应线路钢轨波磨水平,得到频率大于400 Hz时III型轨道减振器扣件及双层非线性扣件的钢轨横向振动大于垂向振动。结合线路钢轨波浪磨耗的特征,在车速65 km/h下中等减振扣件(双层非线性扣件与III型轨道减振器扣件)钢轨波磨多集中在50 mm^80 mm短波长,分析得到III型轨道减振器扣件及双层非线性扣件的钢轨横向动态振动频响峰值与其钢轨波浪磨耗激励的200 Hz^400 Hz频率范围基本吻合,初步得到区段钢轨波磨形成和发展的影响因素。同时,采用锤击方法对比3种扣件轨道结构型式下轨道的振动衰减率及阻尼特性,综合结果发现双层非线性减振扣件相对于其他两种扣件轨道结构型式特别在400 Hz^630 Hz频段范围对钢轨的横向振动有较好的抑制作用。

The intrinsic characteristics of the track are independent of the rolling stock and the traffic conditions.The response behavior of different rail resilient baseplates in metro track system can be identified by the track frequency response function and the decay rate.For the domestic subway line on a tight curved section with three different baseplates,such as double-layer nonlinear resilient baseplate,boned egg baseplate and DTVI2 baseplate,the dynamic vibration response of the rail and the corresponding rail corrugation level under the condition of normal train operation are tested.It is found that in the frequency range above 400 Hz,the horizontal vibration of the rail with the double-layer nonlinear resilient baseplate or boned egg baseplate is greater than the vertical vibration of the rail.According to the feature of rail corrugation waves,for the speed below 65 km/h and the medium damping fasteners(double nonlinear fasteners and boned egg fastener),the rail corrugation is mostly concentrated in the 50 mm-80 mm wavelength.Meanwhile,the lateral vibration frequency response peak of the rail with the double-layer nonlinear resilient baseplate or the boned egg baseplate essentially coincides with that of the rail corrugation wave excitation in the frequency range of 200 Hz-400 Hz.Thus,the influencing factors for rail corrugation initiation and development are preliminarily obtained.Furthermore,frequency response characteristics of track and the attenuation characteristics of the rail with the three kinds of baseplates are tested by hammering method and the results are mutually compared.It is found that the double-layer resilient baseplate has a better vibration suppression effect for lateral vibration of the rail than that of the other two kinds of baseplates,especially in the frequency range of 400 Hz-630 Hz.