Modelling and analysis of vibro-acoustic coupled spaces with a mixed interface

摘要

The eigenmodes of vibro-acoustic coupled spaces with a mixed interface are predicted by the energy principle, in which the mixed interface is composed of an acoustic aperture and the structure with a cutout. Both the vibro-acoustic coupling and the acoustic coupling have been considered in the acoustic vibration analysis owing to the coexistence of sound transmission paths for the structure and acoustic aperture in the coupled system. The transverse displacement of the structure and the sound pressure inside the coupled spaces are, respectively, expressed as two and three dimensional improved Fourier series to ensure the uniform convergence of the solutions over the entire solution domain. The vibro-acoustic coupling energy is composed of the work produced by the interaction of between the coupled spaces and the structure on the rectangular regions decomposed by the aperture position in the establishment of the energy functions for the coupled spaces and the structure with a cutout. The accuracy of the eigenmodes for the vibro-acoustic coupled systems having variable cutouts within the mixed interface is verified against numerical results obtained by finite element method. The influence of the acoustic aperture within the mixed interface on the modal characteristics of the vibro-acoustic coupled system is investigated by the comparisons between the modal results of the coupled system possessing different cutout sizes and cutout positions.