Analysis and prediction of radiated noise of a subway U-beam structure and its noise reduction study
Urban rail transit is the main transportation mode.The problem caused by the noise radiation of subway needs to be solved.Taking a metro-line as an example,the vibration and noise generated by the on-site passing train is measured,and mainly the low-frequency radiation noise caused by U-beam structural vibration is analyzed to establish an acoustic prediction model.The measurement data are verified,and meanwhile the effects of the vibration and noise reduction measures are evaluated.Since the radiation noise of the beam structure is mainly in the low frequency band,the vibration analysis frequency band is 4-200 Hz,and the radiation noise analysis frequency band is 20-200 Hz.According to the analysis result,there is a strong correlation between vibration and radiation noise of beam structure,and their change rules are basically consistent.After installing rail waveguide vibration absorber,both the vibration level and the radiated sound pressure level of the bottom plate are reduced by about 5-8 dB,which shows an obvious vibration and noise reduction effect.Due to the strong directivity of the noise radiated by U-beam vibration,the sound pressure levels are the highest directly above and below the beam body,while it is relatively low at the outside of the beam webs.
rail transitU-beamstructural noisenoise predictionvibration and noise reductionvehicle-track-bridge coupling vibration
NETL
NSTL
万方数据
