Preprocessing of triangulated multiply connected surfaces for quadrilateral mesh generation

Complexly shaped curved surfaces in 3D are commonly encountered in modern materials science and engineering, primarily in the aeronautical, automotive, chemical and other industries. Very often such surfaces are multiply connected and defined by means of their triangulations; the quality of the latter is usually sufficient for rendering, but not for finite element analysis. In order to generate high quality quadrilateral meshes, the surfaces in particular have to be transformed into sets of simple-shaped domains, without internal openings. This paper describes a powerful method and an algorithm allowing transformation of multiply connected curved surfaces of arbitrary geometrical complexity into sets of simple domains. The developed method was implemented as a separate application and turned out to be a powerful practical tool for preprocessing of complex surfaces for consequent mesh generation, including 100% quadrilateral. The paper represents continuation of the authors research activities in that area, earlier completed for 2D cases and published in [Comput. Mater. Sci. 24 (2002) 481].