THE COUPLING OF BOUNDARY ELEMENTS AND FINITE-ELEMENTS FOR NONDESTRUCTIVE TESTING APPLICATIONS

In this paper, the coupling of finite elements and boundary elements, referred to as BEM-FEM coupling, is used to numerically treat a nondes tructive testing (NDT) problem based on eddy currents. BEM-FEM couplin g is especially well suited for NDT problems because it greatly reduce s the discretization effort. A general formulation for such problems i nvolving FEM and BEM is given. The coupling of both methods is achieve d using the boundary conditions on the common boundaries between FEM a nd BEM domains. Only the conducting parts and the exciting coil are di scretized by finite elements. The surrounding air space is taken into account by boundary elements. As an example, problem no. 8 (coil above a crack) of the TEAM workshop (Testing Electromagnetic Analysis Metho ds) is considered.