Necessity of Coupling Finite Element and Boundary Element Methods in Modeling Infinite Soil Mass

by coupling the finite element (FE) and the boundary element (BE) methods, their advantages can be assimilated and their deficiencies can be reduced. Based on this idea a new domain decomposition method has been used here to solve the governing equations separately in FE and BE sub-domains. Both Dirichlet and Neumann boandary conditions are assumed across the interface between the sub-domains. Solution of the governing equations over each sub-domain results in the new displacements and tractions. By imposition of equilibrium and compatibility conditions across the interface, the Neumann and Dirichlet boundary values will be updated and the computations will go on until convrgence achieved. A rigid strip footing over a linear elastic half space is considered to investigate the effect of infinite medium on the results. the area in the vicinity of the footing (near field) is simulated by the FE method and the farther surounding area (far field) is modeled by the BE method. the accoracy of proposed method is studied by the comparing the obtained results with results of the conventional FE method and closed form solution.

Keywords:

Finite Element , Boundary Element , Iterative Coupling , Interface , Strip Footing