Structure-borne noise study of composite steel bridge on high-speed railway

摘要

In order to make out the noise characteristics of steel bridge on high-speed railway, a model which is used to predict the structure-borne noise of a composite steel bridge was established, based on the spatial vehicle-track-bridge coupling vibration theory and the statistical energy analysis (SEA). Then the discipline of bridge-borne noise and the proportion of each component radiating noise were analyzed. Firstly, the hybrid beam-shell FEM model of the bridge was used for vehicle-track-bridge interaction, and then the vibration velocities of bridge deck in time domain was obtained. The velocities in frequency domain by taking FFT technique served as the vibratory energy of SEA deck subsystems. The distribution and transmission of the vibratory energy were obtained by solving the energy equilibrium equations of SEA, and then the sound pressure radiated by the bridge was calculated according to the vibro-acoustic theory. The dominant frequency of composite bridge-borne noise is 20-1000 Hz. The structure-borne noise generated by the ballast composite bridge is higher 3.1 dB than the ballastless concrete box-girder. It is reasonable to neglect the neighbor spans' noise aiming to reduce the element number if the receiving sound point is located in 7.5 in or less to the track centerline. The noise of the bottom flange is less than the other components in all frequency bands. The noise of the longitudinal girder's web is dominant in high frequency range above 315 Hz owing to the high vibration velocity, while the noise in low frequency is governed by the deck.