Tetrahedral mesh generation using advancing front technique and optimization scheme

Abstract

In recent years, applications of the finite element method have significantly increased in the field of metal forming due to the availability of high speed computing devices and improvement of the methodology of finite element analysis. In particular, the demand for three-dimensional simulation has continued to grow through the years. In the analysis of hot forging processes, distributions of temperature and stress in the die set are very important such that these entities should be included in the computations. Here, a fully automatic and robust mesh generator is desirable since die with complex geometries are commonly used in three-dimensional metal forming analyses. In the three-dimensional metal forming analyses, hexahedral mesh element is often used for discretizing work-piece due to its good performance in mapping deformation of the material, while the tetrahedral element is usually used for descretizing die parts due to its advantages in dealing with complicated geometries. To date, many algorithms for fully automatic tetrahedral mesh generation have been developed and used in various fields. The most popular methods of generating tetrahedral elements are the Delaunay method, modified-octree, and advancing front technique. In this study, the advancing front technique has been implemented due to its excellent control of the quality of generated elements, and it has been modified using an optimization scheme. In this optimization scheme, the distortion metric determines `when and where` to smooth, and serves as an objective function. In result, the performance of advancing front technique is improved in terms of mesh quality.