A three-dimensional infinite element for modeling open-boundary field problems

A three-dimensional infinite element is considered which has four nodes and is compatible with conventional cuboids. The infinite element is being developed for exterior potential problems governed by Laplace´s equation. The element is formulated in such a simple way that closed-form expressions for the element matrix are obtained. The element can easily be incorporated into existing finite element codes and its use does not destroy the symmetry and bandedness of the resulting system of equations. Two numerical examples are given