Sound and vibration control of steel-concrete composite beam bridges in high-speed railways using constrained damping layers

This study establishes a vehicle-rail-bridge coupled vibration simulation model based on vehicle-bridge coupling vibration theory to analyze the dynamic responses of the train and bridge. A sound-vibration prediction model for steel-concrete composite beam bridges is developed using Statistical Energy Analysis (SEA, which assumes methods such as subsystem energy balance, weak coupling, high-frequency and statisticality) and bridge structure sound radiation theory. The study investigates the noise reduction effects of constrained-layer damping, focusing on the web plate, which contributes the most to structural noise. Results show that the contribution to noise from the subsystems follows the order: web plate, transverse diaphragm, top plate, bottom plate, and flange plate. The application of constrained damping significantly reduces structural noise across the entire frequency range, with a maximum field noise reduction of 5.5 dB(A). The effectiveness of vibration and noise reduction Nimproves with increasing damping layer and constraint layer thickness, but a nonlinear relationship with an efficiency threshold is observed. The optimal damping thickness is found to be 4 mm for the bridge model considered in this study.