Vibro-acoustic analysis of the annular segment flexible plate coupled with an impedance walled enclosure

This paper proposes a structural-acoustic coupling model which is composed of an annular segment thin plate with various elastic boundary constraints and an acoustic enclosure with rigid-wall or various impedance-wall boundary conditions. The admissible displacement and sound pressure of the coupling system are written as superposition of simple periodic functions on the basis of an improved Fourier series method. The introduction of supplementary polynomials can effectively eliminate the discontinuous or jumping phenomenon in the boundaries. The coupling system is described by constructing energy formulation. Therefore, all the unknown series expansion coefficients can be solved by Rayleigh-Ritz energy technique. The fast convergence of the present method has been given by selecting smaller truncation values. In addition, the accuracy of the present method has been proved by being compared with the finite element method (FEM). The effect of various geometric parameters and boundary conditions on the vibro-acoustic characteristics of coupling system is investigated. Besides, the coupling responses are given by applying the point force on the annular segment plate or point sound source inside the enclosure.