Elastic Wave Propagation Characteristics of 3D Periodic Ballasted Track Structure and Experimental Verification Using Wave Superposition Method

To investigate the elastic wave behavior in high-speed railway ballasted track structures, this paper uses the theory of periodic structures and the generalized plane wave expansion method to establish a 3D periodic ballasted track structure model that incorporates ballast. Subsequently, the wave superposition method is derived to inversely analyze the propagation of elastic waves from an experimental perspective, thereby verifying the accuracy of the 3D periodic track structure model. On this basis, this research calculates and analyzes the energy band distribution of the structure and assesses the influence of ballast structural parameters on the propagation of elastic waves within the track structure. The results show that the generalized plane wave analysis method proposed in this paper closely aligns with the band distribution results obtained by the wave superposition experimental method. There are four local resonance bandgaps identified: 0-62 Hz, 63-138 Hz, 160-169 Hz and 181-224 Hz, in the low-frequency range of the 3D periodic ballasted track. The influence of ballast on the dispersion characteristics of the track structure is mainly observed in the low-frequency range. The shear stiffness of the ballast will enhance the attenuation ability of the structure in the bandgap frequency band; the shear stiffness will increase from 50 kN·mm-1 to 90 kN·mm-1; the total width of the frequency gap will decrease from 180 Hz to 170 Hz; and the reduction rate of the bandgap width will continue to increase. The participatory mass of ballast significantly affects the width of the second- and fourth-order bandgaps. The total width of the low-frequency bandgap decreases by 8.9 Hz when the participatory mass of a single ballast is considered to be 500 kg, and the maximum attenuation of vibration is obtained; when the mass is increased from 500 kg to 800 kg, the total width of the low-frequency bandgap decreases by 8.9 Hz. © 2024 Chinese Academy of Railway Sciences. All rights reserved.