Research For Prediction And Control Of Interior Noise In High Speed Train

In order to improve interior acoustic quality of railway passenger car, this article take the CAD/CAE commercial software as a platform, the high speed train structure - sound system model is established, research for prediction and control of low-frequency noise inside the passenger car is performed on based of FEM and BEM.Firstly,the wordwide research achievements of the vibration and sound are reviewed,and noise of produce and radiation in cab are introduced.Evaluation about noise of EMU is introduced , given the low-frequency noise inside the passenger car numerical calculation of the process.Secondly,the finite element model of the structure body and the dynamic air cavity of railway vehicle was established,then the dynamic characteristic and cavity mode of railway vehicle body was analyzed. Analysis of the seats inside the cavity of the acoustic mode, and pointed out that the structure of the tune resonance frequency.Then,with finite element method, harmonic analysis under 10~200Hz for the car structure model is carried on, The extraction power response result ,interior noise levels are determined using the boundary element method for vibration velocity of panels.SPL distribution of the plane field points under 10~200Hz was given.According to TB1809-86,A-weighted tatal sound pressure level of six reference points in the vehicle were visually displayed as well.The acoustic field distribution of interior vehicle was analyzed,Then,the influence of Sound absorption materials fixed on the boundary of railway carriage was discussed, A-weighted tatal sound pressure level of six reference points under 10~200Hz falls 74.6dB from 83.9dB.Then,using the concept of the acoustic contribution,the element and panel acoustic contribution analysis whether or not the border inside damping material are done to determine the vehicle body region of the vehicle passenger compartment contributing most to the noise levels in vehicle central reference point, identify the main structure-borne noise sources. Hereby the results in this paper can be used to provide theoretical data for structure acoustic design at low-frequency.Finally, considered the air inside the vehicle body structure and interaction,research for prediction of noise in structure-acoustic coupling system of rail car. The mode analysis for the structure model, air cavity model are carried on, giving consideration to structure - acoustic coupling characteristic of the car.Then, acoustic contribution coefficient car body panel at focused frequencies are studied to identify the main structure-borne noise sources,the structure was modified to achieve better noise reduction effect, gives the guidance comment for the structure acoustics design.