Acoustic Radiation Characteristics of Continuous Beam Bridges under Vehicle Bridge Coupling Vibration
To explore the radiation noise characteristics of a continuous beam of an elevated line of urban rail transit and its impact on the surrounding environment,the train bridge coupled vibration theory is combined with the boundary element method for the acoustic radiation analysis of the bridge structure.Taking a three span continuous variable cross-section box girder bridge of an elevated section of Beijing Metro Line 5 as the research object,a calcu-lation program is compiled to solve the vibration response of the bridge,and the vertical vibration calculation results of each span are input into virtual In the lab bridge boundary element model,the radiation noise of continuous beam is solved.Through the combination of time-domain analysis and frequency-domain analysis,the time-domain sound pressure,sound pressure level changes and the spectrum characteristics of the sound radiation of the bridge structure are analyzed.At the same time,compared with the vibration data,the results show that the time history of the noise pressure of the bridge structure is similar to the time history of the vertical vibration acceleration,and the two peaks almost at the same time;It can be seen from the cloud diagram of sound pressure level of each span that the top and bottom of the beam are the areas with the largest noise,and the noise on both sides of the bridge attenuates greatly in the horizontal direction,but does not change significantly in the vertical direction;It can be seen from the frequency domain analysis that the bridge structure noise is mainly low-frequency noise within 200 Hz,and the distribution law of sound pressure level in the frequency domain is similar to the vertical vibration acceleration spectrum.
Urban rail transitVehicle-Bridge couplingContinuous beamVibration responseBoundary element methodRadiated noise
NETL
NSTL
万方数据
