Prediction And Optimization Of The Structure-Borne Low-Frequency Noise From A Rail Transit Trough Girder

With the rapid development of China's economy and the acceleration of urbanization process,the number of urban population has increased dramatically.The conventional way of road traffic has not satisfied people's travel requirements.Rail transit girders have many advantages,such as economy,energy saving,environmental protection,safety,large volume and beautiful appearance.They have been widely used in urban traffic construction both at home and abroad.But the low frequency noise caused by the low frequency is very harmful to the human body,which has caused a large number of complaints from the residents along the line,which has also become an important factor restricting the development of the people.Therefore,it is of great practical significance to study the low frequency noise control of the trench shaped beam structure of urban rail transit.Based on the summary of the domestic and foreign scholars on the prediction and control measures of bridge structure of low frequency noise,analyzing and solving the model using coupled wheel rail excitation,in combining the finite element method and acoustic transfer vector method,vibration and noise characteristics of the beam rail groove is shaped under train load.Then the influence of different structural parameters on the structure noise of the groove beam is studied.Finally,the response surface method is used to optimize the structure of the groove beam,which provides a certain theoretical basis for the vibration and noise reduction of the rail transit beam.The main work of this article is as follows:(1)introduces the development status of city rail transit in China,expounds the necessity of structural acoustic optimization of rail transit Trough Girder,and aiming at the prediction method of bridge structure of low frequency noise and noise control are reviewed and analyzed,pointed out some shortcomings of current research on bridge beam structure noise,finally then introduces the main contents of this paper.(2)the combined simulation method based on ANSYS and SIMPACK is introduced to establish the coupling vibration analysis model of vehicle and bridge,and use it to calculate the vertical force of wheel and rail.Then the modal analysis of the groove girder structure is carried out,and the transient response of the rail beam under the train load is calculated,and the vibration characteristics of the rail beam structure under the train load are analyzed.(3)in the rail transit trough calculated beam structure vibration transient response on the basis of the principle and introduces the calculation of bridge structure noise acoustic transfer vector method,and the low frequency noise of rail slot under train load beam structure radiation was calculated using acoustic transfer vector method.(4)by using the finite element method and acoustic transfer vector method research andanalyzes the influence of different structural parameters on the rail transit trough of low frequency noise of the beam structure,mainly analyzes the effects of low frequency noise,web thickness and web span radius of rail transit trough beam radiation.(5)the response surface method will be introduced into the rail trough girder structure acoustic optimization,this paper introduces the basic principle of the response surface method,and then based on the finite element method and the acoustic transfer vector method to establish the rail groove optimization of beam structure noise low frequency response surface model,combined with the sequence of the two algorithms are optimized section form the rail groove beam acoustic optimization,provides a certain basis for the rail transit trough beam vibration and noise reduction.