Beijing Subway Truck Interior Noise Calculation And Contribution Under The Incentive Of The Wheel-rail

The excessive noise will affect seriously the psychology, physiology and normal life of passenger, it is an inevitable demand to control subway noise for the continuous and harmonious development of subway. Taking the control of the interior train noise excited by track as the goal, thorough researches of interior 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.Taking loads caused by track irregularities as excitement condition, the vibration of railway carriage and noise radiated from vibrated carriage panel were calculated using finite element method and boundary element method, and the distribution rules of sound field in passenger room and cab were obtained, whose characteristics can be shown as follows: The noises of rear passenger room are larger than those of front passenger room, the noises near side panel are bigger than noises near central line; In passenger room, the sound level of the forecast point is biggest near the rear side panel, its value is 65.2 dBA; The sound level of the forecast point is biggest at the rear cab, its value is 75.5 dBA.The characteristic of acoustical contribution degree and the strategy of noise control were discussed. The acoustical contribution degree was calculated of train head of Beijing subway. The results show that the acoustical contribution degree at the certain point caused by certain element is relevant with its vibration amplitude and vibration phase. On the front panel, the third top panel and the fourth bottom panel of passenger room, if construction modification were made or damping materials were coated, the vibrations of these panels can be controlled, so the interior noise of cab and passenger can be reduced.