Abstract:To analyze the influence of dynamic vibration absorber beneath rail base on the sound radiation characteristics of the rail, a vibration-acoustic radiation model for rails was established. First, three-dimensional solid finite element model was established according to the actual topological structure of the railway slab track, and the eigenvalue problem of the rail structure was solved by the direct method. Next, the admittance characteristics of the rail and the decay rate on the track under vertical unit force excitation were calculated and analyzed. Then, the wheel-rail rolling noise prediction model was used to calculate and analyze the influence of rail vibration absorber on the sound radiation power of the rail. Finally, the influence of the parameters of dynamic vibration absorber beneath rail base was analyzed. Results show that the vibration reduction effects of the dynamic vibration absorber beneath rail base were at the frequency band of 750 Hz to 1 650 Hz, and the noise reduction was above 800 Hz. The larger the mass ratio of vibration absorber was, the higher the level of vibration reduction and noise reduction was, while the lower the efficiency improvement of vibration reduction and noise reduction was. Increasing the stiffness of the vibration absorber in a certain range could slightly improve the noise reduction level, whereas too large stiffness could aggravate rail vibration response and its longitudinal propagation. The damping coefficient could affect the frequency bandwidth of vibration reduction and noise reduction, so it needs to be large enough to match the mass and stiffness of the vibration absorber. The calculation and analysis in this paper can provide certain reference for the parameters design of rail dynamic vibration absorbers and the selection of low-noise rails.