Study On Sound Insulation Performance Of High Speed Train Window

The noise generated by the train at high speed seriously affects the comfort of passengers.How to effectively control the noise inside the train is particularly important.In order to reduce the noise inside the car,the noise can be controlled in the sound propagation path.The car window is one of the main paths of noise propagation into the car.By optimizing the structure of the car window,the noise outside the car can be effectively attenuated and isolated.In this paper,the acoustic simulation software such as VA one and Actran are used to study the sound insulation performance of the window structure combined with the relevant acoustic theory.The main work contents are as follows:(1)Based on the finite element method,the statistical energy method,the finite elementstatistical energy hybrid method and the transfer matrix method,the sound insulation prediction model of the window structure is established.Through the simulation calculation,in the midlow frequency range of 20Hz～800Hz,the sound insulation characteristic curve predicted by the finite element model is close to the test result;while in the mid-high frequency range of800Hz～5000Hz,the statistical energy model can better predict the sound insulation performance.Based on the above-mentioned full-band hybrid modeling method,a prediction model for the sound insulation of the window structure of the CRH2 and CRH380 A vehicles was established,the sound insulation characteristics of the windows were calculated and analyzed,and the sound insulation of different types of windows was compared.(2)Calculated and analyzed the sound insulation performance of the laminated glass,established the sound insulation prediction model of the laminated glass in the whole frequency band,and calculated and studied the influence of the glass thickness,the type of the glue and the thickness of the glue on the sound insulation.Further establish the sound insulation prediction model of the full-band window structure,and combine the relevant sound insulation theory to study the sound insulation effect of the main parameters of the window structure,including glass thickness and thickness ratio,cavity thickness and cavity gas.At the same time,the optimal structure of the CRH2 type vehicle window is proposed by considering the factors such as the economy and light weight of the window.(3)Use the VA one software to calculate the acoustic and vibration characteristics of the window structure under the excitation of the turbulent boundary layer,and study the vibration speed and radiated sound power of the inner glass of the window at different running speeds and different distances from the front end of the train.The acoustic and vibration characteristics of the inner glass of the CRH2 window before and after optimization were compared under the excitation of the turbulent boundary layer.The research results show that the sound insulation of CRH380 A windows is better than that of CRH2 windows,and the sound insulation of small windows is better than that of large windows.Compared with ordinary glass,the weighted sound insulation of laminated glass can be increased by 2d B～4d B;the sound insulation performance of laminated glass using PVB material is better than that of SGP material;the difference in glass thickness on both sides of laminated glass can slightly improve the sound insulation performance.For the window structure,the sound insulation performance can be improved by changing the glass thickness ratio and the thickness of the cavity layer;the filling of the inert gas in the cavity has little effect on the sound insulation.Considering the factors of light weight and economy,the weighted sound insulation of the CRH2 window structure after design optimization is increased by 4.7d B.Under the excitation of the turbulent boundary layer,the radiated sound power of the inner glass of the optimized window structure is significantly reduced.