Research On Noise Control And Optimization Of Trough Girder Structural Based On MATV

In recent years,Chinese economic development has been rapid,the process of urbanization is accelerating,and the number of urban population has increased dramatically,resulting in traffic congestion and congestion in the city.However,because of this,it has promoted the rapid development of urban rail transit.Urban rail transit has the advantages of economy,energy saving,environmental protection,safety,and large transportation capacity,and the channel beam has been widely used in domestic and foreign cities due to its better aesthetic performance,more convenient construction requirements,and lower construction costs.Under construction.However,the low-frequency noise generated by it has seriously affected the normal rest and work of the residents along the line,and has received a large number of complaints from residents along the line,which has also become an important factor restricting its development.Therefore,the research on low-frequency noise control of the channel beam structure of urban rail transit has very important practical significance.This paper takes the elevated trench bridge structure as the research object,uses the finite element method to study the vibration characteristics of the elevated trench bridge structure,and combines the boundary element method to introduce the modal acoustic transfer vector analysis to predict the noise characteristics of the elevated trench bridge structure.Analysis of the contribution of state acoustics to find out the main reason for the radiated noise of the elevated trough bridge structure.Starting from the root,the problem of radiated noise of the bridge structure is studied.Provide a new idea for the vibration and noise reduction measures of bridge structure.The main research contents of this article are as follows:1.From the perspective analysis methods and noise control measures of rail transit viaduct structure noise,the research status of rail transit viaduct structure radiation noise is summarized and summarized.Several issues requiring further research are put forward,and the research in this paper is introduced.Main content and technical route.2.A brief description of the harmonic response analysis method for the vibration response of the channel beam structure of the rail transit was established;the finite element model of the channel beam was established and the modal analysis was performed;by establishing the car-rail-bridge of the channel beam Coupling dynamics model,using wheel-rail joint roughness excitation to obtain wheel-rail excitation force using dynamic compliance method;Using the harmonic response analysis in the finite element method,the vibration response of the rail traffic trough beam under the wheel-rail vertical force is calculated,and the vibration characteristics of the trough beam are analyzed.3.The modal acoustic transfer vector method is introduced.Combined with the boundary element theory,the low-frequency noise radiated by the rail transit trough beam structure under the load of the train is calculated.The spectral characteristics of the noise,the spatial distribution of the noise,and the propagation law are analyzed.4.The modal participation factors of the trench bridge structure are analyzed,and the correspondence between the peak sound pressure and the structure modal is found based on the analysis of the modal acoustic contribution,so as to find the largest contribution to the peak sound pressure at the field point.Observe the modal shape of the mode with the largest contribution,and then obtain the corresponding acoustic optimization scheme.5.According to the results of modal acoustic contribution analysis,the structural optimization and improvement of the elevated trough trough bridge structure were carried out,and the improvement based on the single dominant mode shape and the comprehensive optimization improvement based on the first three dominant mode shapes were compared and analyzed.The noise reduction effect of the same target,that is,the change of the maximum sound pressure level of each field point of the optimized model on the basis of the original model,and compared with the two conventional ribbed processing methods,proved that according to the first three dominant vibration modes The feasibility of comprehensive optimization and improvement.