Characteristics Analysis of Sound Radiation of Box Girder Based on Transient Boundary Element Method

Based on the finite element-transient boundary element method, the time-domain vibration characteristics and the acoustic radiation characteristics of a 32 m-span simply supported box girder railway bridge were analyzed. Firstly, the rail-bridge finite element model was established utilizing the finite element software ANSYS, and the wheel/rail force was obtained by the train-track-bridge interaction simulation software (TTBSIM). Then, the wheel/rail force was applied to the finite element model as the external excitation, and the vibration responses of the bridge under the dynamic loading were analyzed. Finally, the radiated noise caused by the dynamic loads was analyzed based on the boundary condition of box girder vibration response by adopting the acoustic boundary element analysis software Sysnoise. Further, the calculated results were compared with the measured ones to valid the model. The results show that when the high-speed train runs at the speed of 200 km/h, the vibration of bridge deck is significantly greater than those of the bottom plate and girder web, and the bridge deck is the main site for noise radiation. The bridge structural noise mainly falls in the range of low frequencies. With the distance increasing, the noise amplitude decreases, and the attenuation of the high-frequency noise is significantly faster than the low-frequency noise.