Optimization of Subway Vehicle Interior Structure-Borne Noise Based on Nodal Contribution Analysis

During the operation of subway, the panels of the vehicle vibrate under external excitation. The radiation noise from the vibration of the panels is the main source of the interior structure-borne noise in low frequency domain. In this paper, the nodal contribution analysis method is used to calculate the influence of the nodes on the peak value of the sound pressure level in the vehicle. The peak sound pressure level of the vehicle interior noise is optimized by modifying the equivalent thickness of the local panels. After reducing the equivalent thickness of some floor panels to 17 mm, the peak value of the radiated noise of each field point generally decreases 2-5 dB. The results show that the nodal contribution analysis is effective when calculating the nodes that contribute the most to the interior noise of the vehicle. And the targeted optimization method which considers the characteristics of car body structure can improve the structure-borne noise level in the vehicle.