Head And Wheel Rail Excitation Of High-speed Train Noise Prediction And Contribution Analysis

The excessive noise of high speed train will affect seriously the psychology, physiology and normal life of passenger and people near the railway, noise pollution has become a bottleneck of restricting high speed railway development, it is inevitable demand to control high speed railway noise for the continuous and harmonious development of railway. Taking the control of the inner train noise excited by track as the goal, systematic and thorough researches of train noise excited by track were carried out.Taken train head carriage, bogies and wheel sets as rigid ones, rail is handled as infinite long Timoshenko beam supported by dispersed sleepers, the coupling dynamics model of vehicle-track of subway has been established. The vehicle vibration has been calculated caused by track irregularities, and three dimensional spatial vibration loads have been obtained at contact points between secondary air spring and car body, the conclusions have been reached as follows:the vertical and lateral vibration amplitudes are greater, and the longitudinal ones are less.A series of models, the finite element model of train head, the acoustical boundary element model of cab and passenger room of high speed train, have been established. The internal and external noises of cab and passenger room caused by track irregularities have been calculated, and the distribution characters of the internal and external noise of cab and passenger room have been ascertained and reached the following conclusion:The noise in cab changes in the range of 64.6-71.6 dBA, outside cab in the range of 45.7-57.8 dBA, in passenger room in the range of 61.9-69.6 dBA, outside passenger room in the range of 45.1-56.8 dBA. At the frequency of 40 Hz and 200 Hz, the sound pressure levels in cab and passenger room are greater. At frequency 40 Hz, the noise contribution of the cab base panel is the biggest for the right ear noise of main driver, whose acoustical contribution coefficient is 47.3%. The noise contribution of the 3th base panel of passenger room is the biggest for field point E, whose acoustical contribution coefficient is 42.4%. Field point E is 0.5 m away from rail central line,0.05 m away from vehicle base,18.8 m away from train head tip. At frequency 200 Hz, the noise contribution of the right side panel of cab is the biggest for the right ear noise of main driver, whose acoustical contribution coefficient is 51.8%. The noise contribution of the 3th right side panel of passenger room is the biggest for field point E, whose acoustical contribution coefficient is 40.9%. To reduce the biggest noise in the cab or passenger room, measure must be adopted at frequency 40 Hz and 200 Hz, which are the decisive frequencies. At low frequency of 40 Hz, it is better to coat with viscoelastic layer on the panel with the biggest acoustical contribution; At low frequency of 200 Hz, it will more suitable to lay good sound absorption material whose performance is good at frequency 200 Hz.