Stable boundary element method/finite element method procedure for dynamic fluid-structure interactions

The stability problem has prevented the application of the boundary element method/finite element method (BEM/FEM) coupling procedure in dynamic fluid-structure interaction problems for the last 2 decades. It has been proved that the linear theta method can make a significant stability improvement for the time domain BEM scheme. With the use of the linear theta method, the BEM/FEM coupling procedure is applied to two-dimensional time domain fluid-structure interaction problems. The fluid domain is acoustic and modeled by taking advantage of the BEM scheme that is suitable to either finite or infinite domains. An internal source has been considered in BEM formulations, and no artificial boundary needs to be introduced for the infinite domain. The structure is modeled by finite elements that can be either linear or nonlinear. Two classical examples are given to show the validity of the coupling procedure in fluid-structure interaction problems and the significant stability improvement given by the linear theta method to the BEM/FEM coupling procedure.