NEW INFINITE ELEMENTS FOR A FINITE-ELEMENT ANALYSIS OF 2D SCATTERING PROBLEMS

Two new formulations of infinite elements are proposed. These elements in combination with the conventional finite elements yield coupled fi nite element formulations for 2D scattering problems. The first formul ation works for any shape of the finite element legion, while the seco nd one has been developed for a rectangular outer boundary. In compari son with the previous infinite elements, the present infinite elements are constructed in such a way that simple expressions have been obtai ned for their element matrices. As a result of this, no formula for nu merical quadrature over the infinite region is necessary and the infin ite elements can easily be incorporated into standard finite element c odes. Two numerical examples are given.