Modelling and numerical solution of elastoacoustic vibrations with interface damping

A nite element method is applied to compute the vibrations of an elastoacoustic system subject to an external harmonic excitation. The e ect of a thin layer of noise damping material between the uid 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 uid 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 nite element method to assess the e ect of introducing a real viscoelastic material to damp the elastoacoustic vibrations of a coupled system