Study On Sound Insulation Performance Of Composite Structure Of High Speed Train

The noise level in the high-speed train will directly affect the passenger’s riding experience.Reducing the noise level in the train is an urgent problem to be solved.The main method to reduce the noise value in the vehicle is to take measures on the transmission path of the noise.If the vehicle body structure can effectively block the noise,it can effectively reduce the noise in the vehicle and improve the comfort of passengers.Multilayer carbon fiber composite structure has the advantages of high strength and low density.Its structure is complex,and it is difficult to accurately calculate the law between its sound insulation and design parameters.Therefore,it is of great significance to analyze the sound insulation performance of carbon fiber composite structure.In this paper,the sound insulation calculation and analysis model of aluminum profile and the sound insulation calculation and analysis model of multi-layer carbon fiber composite structure profile are established.The low-frequency sound insulation calculation is carried out by using the finite element method and actran software in the low-frequency band of 100Hz-800Hz;In the medium and high frequency band of 800Hz-5000 Hz,the statistical energy method is used to calculate the medium and high frequency sound insulation with VA one software.The main work contents are as follows:(1)The sound insulation performance of aluminum profile was studied.Based on the finite element method,the finite element(FEM)model of aluminum profile is established in the medium and low frequency range of 100Hz-800 Hz,and the statistical energy analysis(SEA)model of aluminum profile is established in the medium and high frequency range of800Hz-5000 Hz based on the statistical energy method.The full frequency sound insulation loss of aluminum profile is calculated,and the sound insulation performance curve of aluminum profile is obtained;The weighted sound insulation loss of aluminum profile is calculated by Excel method;The causes of sound insulation trough of aluminum profile are analyzed;The effects of upper plate thickness,lower plate thickness,plate reinforcement thickness,plate reinforcement angle and cavity thickness on the sound insulation performance of aluminum profile are studied by using the control variable method.The results show that the sound insulation of aluminum profile structure can be improved by appropriately reducing the angle of plate reinforcement and increasing the thickness of cavity,and the weight of the structure can not be increased.(2)The sound insulation performance of multi-layer carbon fiber composite structural profile was studied.Based on the finite element method,the finite element(FEM)model of carbon fiber profile is established in the medium and low frequency band of 100Hz-800 Hz.Based on the statistical energy method,the statistical energy analysis(SEA)model of carbon fiber profile is established in the medium and high frequency band of 800Hz-5000 Hz.The sound insulation capacity of carbon fiber profile in the whole frequency band is calculated and the sound insulation performance curve of carbon fiber profile is drawn;The weighted sound insulation loss of carbon fiber profile is calculated by Excel method;The causes of sound insulation trough of carbon fiber profile are analyzed;The control variable method is used to explore the influence of the parameter changes of each part of the carbon fiber profile on the sound insulation,and the effects of the structural parameters of the thickness of the upper carbon fiber board,the thickness of the lower carbon fiber board,the thickness of the plate reinforcement,the paving scheme of the carbon fiber board and the thickness of the single layer of the carbon fiber board on the sound insulation performance of the carbon fiber profile are explored respectively.The results show that the sound insulation of carbon fiber profile structure can be better improved by optimizing the laying scheme of fiberboard and appropriately increasing the thickness of each layer of carbon fiber board.(3)The sound insulation performance optimization of aluminum profile and carbon fiber profile is studied,and the correctness of the calculation is proved by comparison with the literature.The sound insulation performance of carbon fiber profile and aluminum profile with the same size and specification is compared and analyzed.The calculation results show that aluminum profile has better sound insulation performance than carbon fiber profile.