Volume Discretization into Tetrahedra - II. 3D Triangulation by Advancing Front Approach

Computers and Structures, Pergamon, Vol 39, Num 5, pp.501-511, 1991

MESHING
RESEARCH
CORNER

Department of Civil and Structural Engineering, University of Hong Kong, Hong Kong

Abstract
Existing methods of automatic mesh generation for 3D solid objects are reviewed. Although the 3D Delaunay triangulation recently aroused much attention. its suitability as a finite element mesh generator is questioned. Although in 2D Delaunay triangulation. the 'max-min' angle criterion can be verified over the entire domain, no equivalent or similar criterion can be defined for its extension to 3D situations to ensure that tetrahedron elements so generated are well proportioned for numerical calculations.

In this paper, a simple but versatile 3D triangulation scheme based on the advancing front technique for the discretization of arbitrary volumes is presented. To ensure that the tetrahedron elements generated are as equilateral as possible, the ratio of volume of the element to the sum of squares of edges put into a dimensionless form is adopted to judge the quality of a tetrahedron element. The qtialitv of the finite element mesh can thus be ensured if the shape of each tetrahedron element is carefully controlled in the mesh construction process. Through the study of numerous examples of various characteristics. it is found that high-quality tetrahedron element meshes are obtained by the proposed algorithm.