Prediction And Control Of Interior Noise Of Super-high-speed Train Based On Hybrid FE-SEA Method

In this thesis, interior noise over a bogie area of super-high-speed train is researched based on the hybrid FE-SEA method, and then a hybrid model is built by the Vibro-Acoustic analysis software (VA One) to simulate and predict the interior noise. Overall, this model is valid by comparing results to measurements in reality.Specifically, by this hybrid prediction model, the interior noise is comprehensively analyzed. Firstly, the contour of sound pressure is calculated to investigate the spatial distributions of interior noise with diverse frequencies. After it, the spectrum characteristic of sound pressure level and the spatial distribution of overall sound pressure level are also studied. In order to control interior noise, the contribution of power input and noise transmission paths are researched to identify the main sound sources and paths of the noise to the interior. Results show that interior noise level of upper acoustic cavities around pantograph base area is mostly significant. The sound pressure level decreases gradually with the increase of frequency, and there exist local peaks around100Hz and1250Hz. The excitation loads around pantograph area and bogie contribute to main sound sources of interior noise. In addition, for windows, the radiation of vibration sound has a large influence on high frequency noise.Finally, the sound-absorbing coefficient of carpets in high-speed trains is measured by standing wave tube, and its effect on interior noise is studied. Meanwhile, the influence of sound-absorbing structure consisted of micro-perforated panel and ceiling is researched. From results, it is concluded that the sound-absorbing material has a good performance on high-frequency sound absorption, but doesn’t work well on overall sound pressure level. The micro-perforated panel and ceiling make up of the sound-absorbing structure which can not only effectively absorb low and mid frequency interior noise but also largely reduce the overall sound pressure level.