A NEW MAPPED INFINITE WAVE ELEMENT FOR GENERAL WAVE DIFFRACTION PROBLEMS AND ITS VALIDATION ON THE ELLIPSE DIFFRACTION PROBLEM

The theory for an improved infinite element for wave diffraction is pr esented. The improvement is on the original wave element presented by Bettess, Zienkiewicz and others. The modification involves the introdu ction of one extra term in the original shape function derivatives and a change in the numerical integration sequence. The modification enab les the element to be used with elliptical and other non-circular mesh es. Similar mappings have already been used with wave envelope infinit e elements by Astley and others, As a test of the element, accurate re sults are demonstrated for a range of elliptical cylinder diffraction problems. The element has not yet been tested for other non-circular p roblems. (C) 1998 Elsevier Science S.A. All rights reserved.