A Finite Element Approach For Calculating Sound Pressure Level In A Coupled Structural Acoustic System

In this study, the sound-structure interaction problem in a coupled structural-acoustic system has been investigated. The novelty of this investigation is embedded in using of Finite Element Method to calculate sound pressure level. The governing differential equation for the interaction of the acoustic cavity with the flexible wall (plate) is calculated. The modal analysis of such a problem is possible, an analysis in which the decoupled equations of motion for the cavity and the flexible wall can be obtained separately. In order to accomplish this task, the coupled structural-acoustic system has been decomposed to an acoustic component, a cavity with a rigid wall, and a structural component, a flexible wall (plate). The cavity modes (eigenvalues and eigenvectors) of the cavity with the rigid wall boundary condition and structural modes of the simply supported flexible plate in a vacuum are obtained by using the finite element method. The coupled structural-acoustic equation for the pressure inside the cavity is obtained in terms of the eigenmodes of the cavity and the flexible wall. The coupling method has been successfully implemented into two classical existing problems.