高速铁路有砟轨道结构振动带隙特性及其对振动传递的影响

Vibration band gap characteristics of high-speed railway ballasted track structure and their influence on vibration transmission

为探究三维周期轨道结构中弹性波的传播规律,实现对轨道结构振动噪声的合理调控,本文根据周期结构理论,以Timshenko梁、Mindlin板梁波动理论为基础,采用三维平面波展开法,建立包含道砟在内的三维周期轨道结构模型,并依据波叠加法进行力锤敲击实验验证模型的正确性。利用该模型对轨道结构进行弹性波模态和参数分析。本文提出的广义平面波解析法与波叠加试验方法得到的结果基本吻合,该试验方法对三维周期轨道频散特性研究具有较好的适应性。结果表明:提高道砟剪切刚度会增强结构在带隙频段内的衰减能力,剪切刚度从0.05 MN/mm增加到0.09 MN/mm,带隙宽度减小率从0.06 Hz/MN增加到0.21 Hz/MN;振动衰减频段宽度在道砟参振质量为500 kg时对振动的衰减最多。当负载激励频率在频率间隙带内但接近通带时,出现异常多普勒效应。高速铁路有砟轨道低频带隙对高速列车的衰减能力要高于对低速列车的衰减能力,高频段带隙对高速列车的衰减能力要低于对低速列车的衰减能力。

To explore the propagation characteristics of elastic waves in a 3D periodic track structure and propose a vibration and noise control method,this paper adopts the 3D plane wave expansion method to establish a 3D periodic ballasted track structure model using the periodic structure theory,Timoshenko beam wave theory and the Mindlin platebeam theory.The wave superposition method was used for hammer impact test to verify the correctness of the theoretical model.This model was used for elastic wave mode and parameter analysis of track structures.The generalized plane wave analytical method proposed in this paper was consistent with those measured experimentally in the wave superposition test.The results show that the proposed testing method was suitable for studying the dispersion characteristics of 3D periodic track structures.Increasing the ballast shear stiffness enhances the structure attenuation capacity in the gap frequency band;When the shear stiffness increases from 0.05 to 0.09 MN/mm,the band gap width reduction rate also increases from 0.06 to 0.21 Hz/MN.The width of the vibration attenuation frequency band is affected by the ballast mass with the maximum vibration attenuation at 500 kg.The condition for an abnormal Doppler effect can be obtained by changing the excitation frequency relative to and band gap frequency.