Contributions separation prediction for multi-dimensional vibration transmission in the bogie system to metro interior noise

Separation of noise source contributions is critically important for the acoustic performance optimization and design of rail vehicles. This paper establishes a refined multi-component train dynamics model, a broadband noise prediction model, and a wheel–rail rolling noise prediction model to conduct layer-by-layer vibration transfer analysis of the vehicle, achieve contribution separation of structure-borne and air-borne noise, and further perform multi-component vibration-noise contribution separation for the bogie system. The results show that the transfer path analysis (axle-bogie-body) confirms hierarchical amplification, and vertical vibrations are governed by body heave/pitch and roll modes. Below 100 Hz, the structure-borne sound path (caused by wheel–rail vibrations) contributes more than 95% of the sound energy, while above 100 Hz, the air-borne sound path (caused by wheel-rail noise) contributes more than 97% of the sound energy. Among the contributions of structure-borne sound components, below 250 Hz, the most significant contributing component is the secondary vertical damper (16–250 Hz), with an energy proportion of 55%∼99%; the anti-yaw damper makes an important contribution in the 16–40 Hz range, with an energy proportion of 24%∼40%. This research work holds significant importance for implementing precise noise control and ensuring the low-noise design of vehicles.