Model reduction for efficient FEM/BEM coupling

Model reduction techniques seek approximate solutions of a problem with a large number of DOFs within a subspace of small dimension. Component Mode Synthesis (CMS) methods form a large class of reduction methods where the subspace is selected a priori. Introducing a posteriori error estimation and iterative correction significantly extends the range of applications of reduction methods. The paper focuses on possible uses of reduction methods for coupled Finite Element (FEM) / Boundary Element (BEM) predictions in cases where the boundary contains a significant number of Degrees Of Freedom (DOFs) and where the coupling significantly affects the response of the structure. Issues addressed, for the case of a reactor building, are error evaluations for the coupled responses when using a FEM model reduced a priori and performance evaluations when using an iterative scheme that guarantees a given level of error.