The Transfer Paths’ Contribution Analysis to Floor Vibration of Metro Vehicle

Abstract

Noise control is one of key issues to improve the ride comfort of metro trains. To find out the excitation source and its transfer path is an important prerequisite for noise control. The sound source identification results found that the significant noise source in metro trains is the structural-borne sound radiated by floor vibration. Based on the OTPA method, this study presents a method considering the amplitude and phase of the excitation to analyze the contribution of the secondary suspension path to the floor vibration. The results show that the energy of the passenger room noise mainly concentrates on the frequency range of 300~800Hz, caused by floor vibration; in the frequency range of 300~800Hz, the vertical direction of the anti-rolling torsion bar area provides the maximum contribution to the floor vibration, followed by the longitudinal direction of the air spring area. On the basis of contribution analysis, a transfer path optimization scheme is proposed, which may provide reference for future metro trains noise control.