Abstract:
[Objective] In recent years, due to the influence of urban planning and layout, the number of small-radius curve tracks in urban rail transit construction is gradually increasing. To address the vibration and noise issues associated with small-radius curve tracks, it is necessary to study vibration and noise reduction measures and evaluate their effectiveness. [Method] Using the small-radius curve track section on a certain urban rail transit line in Beijing as research object, a vehicle-track-bridge coupled dynamics model and a rail finite element-boundary element acoustic radiation model are established by finite element and boundary element methods, respectively. Vibration and noise control measures for small-radius curve tracks are proposed,including specifically rail seamless welding and replacement with higher-grade vibration-damping fasteners. A simulation analysis of vibration acceleration and vibration levels after implementing the control measures is conducted to verify their effectiveness. Focusing on the primary source of train noise―wheel-rail noise, the inherent frequency, vibration modes, and acoustic radiation of the rail are calculated and analyzed based on the rail finite element-boundary element acoustic radiation model, and the wayside acoustic radiation before and after implementing vibration and noise reduction measures is compared. [Result & Conclusion] After applying the rail seamless welding vibration and noise control measure, the maximum vibration acceleration of the track bed decreases by 0.35 m/s2, and the maximum vibration level decreased by 1.42 dB. After replacing with higher-grade vibration-damping fasteners, the vibration acceleration of the track bed decreases by 1.05 m/s2, and the maximum vibration level decreases by 7.29 dB. The wayside sound pressure level decreases by 4.93 dB(A) after implementing the vibration and noise control measures.