Efficiency increment in 3D multi-zone boundary element algorithms by use of iterative solvers

In this work general aspects of developing efficient generic multi-zone BEM algorithms are discussed, focusing specifically on three-dimensional formulations. The main idea followed in the article for coupling a certain number of subregions discretized with boundary elements is that the global sparse matrix of the coupled system is implicitly considered, without condensing the problem quantities into the interface variables and also without manipulating any of the zero blocks appearing in the system matrix. Thereby an algorithm, optimum in respect to storage requirements, is developed. Also, the performance of the proposed coupling algorithm is further increased by making use of iterative solvers. Recently reported research emphasizing the efficiency of such solvers in comparison with direct ones and the results obtained in this paper for a simple 3D elasticity problem are used to show the efficiency of the multi-zone BEM strategy presented.