Implementation of FE-BE Hybrid Techniques into Finite Element Programs
Infinite boundary elements (IBE) in both 2-D and 3-D have been implemented in a general purpose finite element program for use in conjunction with finite elements (FE) to solve unbounded magnetic field problems. The advantage of the IBE’s, in addition to reduced model size, is that they do not destroy the bandedness of the finite element matrices as do boundary elements (BE). In contrast to the infinite finite element (IFE) usage, these IBE’s do not require definition of nodes in excess of the ones already introduced for the interior FE domain, thus simplifying modelling efforts further. The IBE formulations presented here produce unsymmetric matrices. An attempt is made to symmetrize the IBE matrices. The example problems presented demonstrate that the loss of accuracy in solutions due to the symmetrization is insignificant.
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