Structure-Borne Noise Sound Source Identification Of High-Speed Railway Bridges

With the continuous advancement of high-speed railway construction,noise pollution is an issue that cannot be ignored in the development of high-speed railway,among which bridge structure noise is one of the important sources of high-speed railway noise.For a long time,relevant research has mainly focused on wheel/rail noise,while less research has been conducted on bridge structure noise.In this paper,the noise sources of high-speed railway track bridge structures are taken as the research object.Based on the equivalent source near field acoustic holography technology,the low-frequency information of bridge structure noise is obtained,and the bridge structure noise sources are identified.The numerical simulation of bridge structure noise is conducted using ANSYS finite element software and LMS Virtual lab acoustic response software.The acoustic radiation characteristics of bridge structures are studied,and the impact of different loading methods on the identification of bridge structure noise sources is analyzed.The main research contents of this article are as follows:(1)Based on the theory of near-field acoustic holography based on spatial sound field transformation,numerical simulations are conducted for single and coherent sound sources,and the effects of different parameter selections on the accuracy of sound source recognition and reconstruction are studied.(2)Based on the theory of near-field acoustic holography with equivalent sources and the near-field data extrapolation method,numerical simulations of single sound source,coherent sound source,and simply supported plate sound source have been conducted to verify the correctness and effectiveness of the method for sound source identification.(3)Using the finite element software ANSYS and the acoustic software LMS Virtual lab,a noise prediction model for box girders was established.Based on the dynamic response of the bridge,in-depth research was conducted on the acoustic radiation characteristics of the box girder bridge,including the sound field distribution,sound propagation rules,and the acoustic propagation contribution of each panel.(4)The acoustic information on the surface of a box girder bridge is simulated using the acoustic software LMS Virtual lab,and the equivalent source near-field acoustic holography theory is introduced for calculation.The surface acoustic pressure nephogram of each component of the bridge is obtained,and compared with the LMS derived results.The correctness of the algorithm is further verified,and the distribution rules of the bridge surface acoustic sources under different loading conditions are analyzed.The research results of this article have certain reference value for high-speed railway noise control and also provide new ideas and methods for research in related fields.