Modelling and numerical solution of elastoacoustic vibrations with interface damping

Abstract

A finite element method is applied to compute the vibrations of an elastoacoustic system subject to an external harmonic excitation. The effect of a thin layer of noise damping material between the fluid and the solid is taken into account by relaxing the interface kinematic condition of perfect contact. We consider the non-linear eigenvalue problem arising from the free vibration problem for the damped system. For the case of a fluid in a rectangular rigid cavity with one absorbing wall, we deduce the dispersion equation which allows computing analytically its eigenvalues and eigenmodes and compare the numerical solution with them. Finally, we apply the finite element method to assess the effect of introducing a real viscoelastic material to damp the elastoacoustic vibrations of a coupled system. Copyright © 1999 John Wiley & Sons, Ltd.