Sound Field Calculation Of High-speed Train’s Cab And Analysis Of Noise Reduction

With the progress of science and technology, the development of high-speed railway in China is very fast. With the increase of the train speed, the noise is also increasing, and the noise of the train is also starting to be valued.At present, there are many researches on the high speed railway noise and noise reduction methods, but the research is not particularly detailed, and the better noise reduction scheme remains to be studied. In this paper, the indoor noise of the cab is studied when the train is running in high speed, and some new noise reduction methods are put forward and the effect of noise reduction is finally evaluated.The paper establishes the cab structure model and finite element acoustic finite element model, analyses the modal and acoustic solid coupling modal by Hypermesh. According to the air excitation, the vibration response of the structure of the cab in 1000 Hz is calculated and the vibration response is also analyzed.According to the acoustic finite element method, the acoustic field inside the driver’s room in 1000 Hz is calculated by Virtual.Lab. The acoustic field distribution cloud image is obtained, and the area in which the acoustic pressure level is very high in the cab is analyzed.The acoustic pressure response curve of three sites near the driver is calculated and analyzed. The comparison of the response curves of the simulated responses and the measured responses of the sound pressure response curves prove that the simulation analysis is right.The paper analyses the response quantity of the cab plate contribution to the field sound pressure, and determines the plate with large contribution. The acoustic transfer vector is calculated and the ATV function is analyzed.According to the ATV theory, the acoustic field is analyzed.According to the experiment, the absorption coefficient of porous sound-absorbing material is tested, theoretical and experimental method is used to analysis the influence of single micro perforated panel structure parameters on the sound absorption coefficient, the composite micro perforated sound absorption performance of the plate structure is test, through comparison the paper finds the best absorption scheme. To optimize the cab well shaped skin stiffened plate structure, the paper comparatively analyses the well shaped, rice shaped and U shaped skin rib structure’s vibration and acoustic radiation characteristics and sound insulation properties,and get the optimal structure types. The effect of free damping and damping of the parameters on the noise reduction is analyzed, and the merits and disadvantages of free damping and damping are also analyzed.The effect of noise reduction is evaluated when the sound absorption strcture, damping and rice shaped structure are used respectively in the cab. At last, the total noise reduction method is proposed and the effect of total noise reduction is evaluated.