Simulation of Vibroacoustic Problem Using Coupled FE/FE Formulation and Modal Analysis

Vibroacoustic consists of the interaction between elastic and acoustic waves. This interaction causes the acoustic pressure to exert a force to the structure and the structural motion produces an effective fluid load. Hence, studying vibroacoustic problems requires that both elastic structure and fluid to be modeled. In this paper, a simple vibroacoustic problem is modeled by a coupled FE/FE modal analysis method in which a lumped mass representation is considered. The numerical results are represented for an elastic plate backed cavity. In this method, the coupling system is projected on some structural modes in vacuum and some rigid cavity modes. The obtained system is put in a diagonal form by solving left and right eigenvalues problem. Some results are presented to illustrate the effect of the modal analysis and the lumped mass formulation. Some numerical results were compared to analytical solutions.