IMPROVED ADAPTIVE QUADRILATERAL MESH GENERATION USING FISSION ELEMENTS

An improved technique for quadrilateral mesh generation using an appro ach based on fission elements is presented. Considerable work has been carried out by Zhu et al.(1) [Zhu, J. Z,, Zienkiewicz, O. C., Hinton, E. & Wu, J., A new approach to the development of automatic quadrilat eral mesh generation. Int. J. Numer. Meth. Engng, 1991, 32, 849-866] i n applying the advancing front technique to quadrilateral mesh generat ion. In this paper more details of the specific characters of quadrila teral elements and an improved mesh generation technique in which the final quadrilateral elements are accurately generated according to ele ment size parameters, are presented. A new kind of transition element called fission elements are used in this quadrilateral element generat ion technique. These elements are used when two subfronts which both h ave an odd number. Active sides are formed after two triangles have be en generated and combined to form a quadrilateral. This avoids having to add an extra constraint during the mesh generation and guarantees t hat the quadrilateral mesh generation is as easy as triangular mesh ge neration. Some new techniques for quadrilateral element mesh enhanceme nt are proposed. All of these are demonstrated by a variety of example s. (C) 1998 Elsevier Science Ltd and Civil-Comp Ltd. All rights reserv ed.