A Coupling of FEM-BEM for Elastic Structure in a Transient Acoustic Field

We propose in this paper a space-time variational formulation for the scattering problem of transient acoustic waves in a fluid medium with a submerged elastic object. The problem is first reduced to a coupling problem between partial differential equations and boundary integral equations and an energy formula given in terms of the unknowns of this coupling problem. The variational formulation follows then. A space-time finite element method based on this formulation gives rise to a time-stepping scheme with both volume and surface spatial elements as variables.