Analysis of the vibro-acoustic behaviors of the periodically stiffened double panel-cavity coupled system

Abstract

The vibro-acoustic behaviors of the periodically stiffened double panel-cavity coupled system is analytically investigated by the energy principle, in which the coupled system is composed of double panels, cavities and stiffeners between the face panels. In the theoretical modelling, the upper and bottom panels are decomposed into incident sub-panels and radiated sub-panels, respectively. The coupling energies between the sub-panels and stiffeners are proposed in the establishment of the energy functions for the periodically stiffened double-panels structure. To ensure the convergence and continuity over the entire solution domain, the two and three dimensional improved Fourier series are respectively adopted to express the displacement functions of the structures and the sound pressure functions inside the cavities in the coupled system. The effectiveness of the theoretical modelling of the coupled system is validated by the comparision of the natural modes and vibro-acoustic responses of the periodically stiffened double panel-cavity coupled system predicted by the current method and the ones obtained from finite element method. The number of stiffened panels has great influence on the sound transmission loss of the coupled system. In addition, the effect of the coupling stiffness and the acoustic medium on the sound transmission loss of the coupled system are also discussed in the numerical analysis.