A rigorous error analysis of coupled FEM-BEM problems with arbitrary many subdomains

Abstract

In this article, we provide a rigorous a priori error estimate for the symmetric coupling of the finite and boundary element method for the potential problem in three dimensions. Our theoretical framework allows an arbitrary number of polyhedral subdomains. Our bound is not only explicit in the mesh parameter, but also in the subdomains themselves: the bound is independent of the number of subdomains and involves only the shape regularity constants of a certain coarse triangulation aligned with the subdomain decomposition. The analysis includes the so-called BEM-based FEM as a limit case. © 2013 Springer-Verlag Berlin Heidelberg.