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

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 plate-beam 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.