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Firstly, FEM (Finite Element model) of the aluminum profile is built. The structural material parameters are then given to compute the free modals. After the comparison with the experimental results, the relative error of the modal frequency can be controlled within 5 %, which meets the requirements of CAE analysis. Secondly, pulse decay method is applied to measure damping loss factor of the aluminum profile. As shown from the results, its damping loss factor is 0.15 %-0.35 % within 0 Hz-1600 Hz, which can be used as the input parameter in the subsequent computation of the transmission loss. Thirdly, FE-SEA hybrid method is used to compute the transmission loss of the aluminum profile. As known from the computational results, the transmission loss troughs of the aluminum profile are appeared at 160 Hz, 400 Hz and 800 Hz, whose change trend is basically consistent with the experimental results. Therefore, the sound insulation performance of the aluminum profile at middle and low-frequency band can be reasonably predicted by the simulation model. Finally, based on the verified model of the aluminum profile, the optimization design is conducted on its acoustic-vibro performance from the following aspects such as sound-bridge, plate thickness and structural materials. As a result, a structure with relatively optimal acoustic-vibro performance is obtained. [ABSTRACT FROM AUTHOR]

Taking the standard wheel model as an example, the radiation noise of a single wheel under excitation force which is computed by multi-body dynamics model is computed by acoustic boundary element method (BEM). Then, the damped wheel is proposed, and the sound radiation characteristics of both wheels are analyzed and compared. The results show that sound field of a single wheel presents an obvious directivity with petaloid change and continuous decrease, and the wheel tread and web contribute the most rolling noise. Compared with the standard wheel, the acoustic radiation power of the damped wheel decreased significantly, especially at the peak frequency. After that, the radiation noise generated by the wheel in the train is researched. The results show that the radiation noise generated by the wheel in the train is a complex sound field after the superposition and interference of multiple wheel noises, which are mainly in the bogies at both ends and its vicinity region. Meanwhile, the basic directivity characteristics of the petaloid change and continuous reduction are remained. The radiation noise which is generated by the wheel in the train has obvious peak characteristic, whose corresponding peak noises are below 110 dB. The radiation noise of the damped wheel is significantly smaller than that of the standard wheel at most frequency bands, and the total SPL at the observation point has decreased by 14.5 dB with obvious noise reduction effect. In order to further research the radiation noise of the damping wheel, influence factors on the noise reduction are analyzed. Finally, these parameters such as thickness and material should be considered comprehensively during designing the damping wheel, in order to find the optimal combination of all parameters. [ABSTRACT FROM AUTHOR]