An Iterative Decomposition Coupling Algorithm Between TD-FEM and TD-BEM with Independent Spatial Discretization on the Interface

In order to make good use of the inherent advantages of the FEM and the BEM formulations, an iterative decomposition coupling algorithm between time-domain FEM and time-domain BEM with independent spatial discretization on the interface is proposed for elastodynamic problems. In the coupling process, based on the conditions of the displacement continuity and the force equilibrium on the interface, the force and the displacement converting matrices are obtained. Data are exchanged on the interface between the time-domain FEM variables and the time-domain BEM variables through the converting matrices, instead of the interpolation calculation for the variables between the two sub-domains. Releasing the limitation of the interpolation function of variables on the interface, the proposed coupling algorithm is easily manipulated in data exchange between nodal variables on the interface. Additionally, the independent spatial discretization on the interface suitable for one's own boundary conditions and material properties in both the TD-FEM and TD-BEM sub-domains, the proposed coupling algorithm is of good versatility and computational efficiency. Three benchmark examples are presented to verify the correctness and efficiency of the proposed coupling algorithm.