Development of special finite elements for free boundaries

Abstract

A modified two-dimensional quadrilateral plane stress element and a modified three-dimensional brick element have been developed to eliminate the weakness of the conventional finite elements in determining the stress distributions along free boundaries. The results obtained by the said modified elements are in good agreement with the theoretical and experimental results and are superior to the conventional finite element results. A comparison is made between the proposed approach of improving stress calculations and another approach which employs the least square fitting method. The comparison shows that the two approaches provide comparable accuracy but the latter is more difficult to implement. © 1998 Elsevier Science Ltd. All rights reserved.