Abstract: The model of sound radiated from a rectangular enclosure consisted of two elastic supported flexible panels and four rigid panels is deduced by using Hamiltonian function and Rayleigh-Ritz method. By means of continuous distributions of artifical springs along boundary of flexible panels, this model allows the consideration of a wide variety of boundary condi-tions and structure joint conditions. Analytical results on the radiation of sound are presented. These results are intended to investigate two main issues: one is the coupling of the com-bined structure is relatively weak, so the radiation of sound is controlled by panel which is directly excited, the other is the translational stiffness affects the radiation of sound more than the rotational stiffness does. Then, modes of sound pressure and flexible panel are obtained by FEM. Modal coupling coeffici- ents are synthesized. Finally, the responses of sound pressure is worked out by BEM. The result of the simulation method coin-cides well with the analytical result, and is satisfactory.

Key words: Coupling, Elastic support, Numerical simulation, Radiation of sound, Rectangular enclosure