ELASTOACOUSTIC ANALYSIS OF SUBMERGED FLUID-FILLED THIN SHELLS

The analysis of fluid-filled thin shells is discussed in this paper. It is well known that a boundary element formulation of the exterior acoustic problem becomes ill-conditioned at certain critical frequencies. For a coupled boundary-element/finite element formulation of the coupled elastocoustic problem the formulation suffers from the same numerical ill-conditioning. However, for fluid-filled thin shell problems the resulting coupled formulation is unique at all frequencies. In this paper the condition numbers of the coupled and uncoupled formulations are calculated and the uniqueness of the coupled formulation is demonstrated for submerged fluid-filled thin shells.