Internal low-frequency noise analysis of high-speed train under mechanical excitation

With the speeding up of high-speed trains, the radiation noise generated from plates of the vehicle body was becoming increasingly obvious; however, fewer researches were performed on this aspect at present. The dynamic equation of the head vehicle of the high-speed train and the vehicle-track coupled dynamic model were both established, and then the dynamic load excitation of the vehicle body on uneven tracks was eventually obtained. With the material properties attributed, the finite element model of the vehicle body was eventually obtained to solve the modal, which was subsequently compared with the experimental one to verify the accuracy of the model. Based on the structural-acoustic coupling boundary element method, the noise distribution inside the passenger compartment of the high-speed train was calculated. Moreover, with the employment of the acoustic transfer vector (ATV) technology, the contribution coefficients of each plate of the vehicle body to the maximum sound pressure point were calculated. It was shown through the result that when the sound-absorbing materials inside the vehicle were ignored at the speed of 300 km/h, the sound pressure level inside the high-speed train ranged between 80 dB and 93 dB. Furthermore, when transverse ribs were added to the passenger compartment floor, its contribution coefficient to the sound pressure at the field points could be reduced, thus the noise inside the high-speed train could be improved.