Coupled BE-FE Scheme for Three-Dimensional Dynamic Interaction of a Transversely Isotropic Half-Space with a Flexible Structure

The response of structures bonded to the surface of a transversely isotropic half-space (TIHS) under the effect of time-harmonic forces is investigated using a coupled FE-BE scheme. To achieve this end, a Finite Element program has been developed for frequency domain analysis of 3D structures, as the first step. The half-space underlying the structure is taken into consideration using a Boundary Element technique that incorporates half-space surface load Green’s functions for a transversely isotropic medium. Next, the two programs are combined using a direct coupling algorithm and the final program is obtained. To validate the results, some benchmark problems are solved with the FE and the BE programs, separately and then the coupled technique is checked with the results of some special cases for which the solutions are available in the literature. At the end, a parametric study is carried out on several common types of structures to study the effects of the degree of anisotropy of transversely isotropic soil medium on the dynamic behavior of the structure. Moreover, the effect of soil-structure interaction (SSI) on the natural vibration frequency of the structures is also studied.