Finite element computation of three-dimensional elastoacoustic vibrations

In this paper, the interior elastoacoustic problem in a 3D domain is solved. Displacement variables are used for both the fluid and the solid. To avoid the typical spurious modes of this formulation, a non-standard discretization is used, consisting of classical linear tetrahedral finite element for the solid and Raviart-Thomas elements of lowest order for the fluid. A new unknown is introduced on the interface between solid and fluid to impose the transmission conditions. (C) 1999 Academic Press.