Tetrahedral meshes are being extensively used in finite element methods (FEM). This paper proposes an algorithm to generate feature-sensitive and high-quality tetrahedral meshes from an arbitrary surface mesh model. A top-down octree subdivision is conducted on the surface mesh and a set of tetrahedra are constructed using adaptive body-centered cubic (BCC) lattices. Special treatments are give...

A composite C tetrahedral finite element is developed which does not have any edge degrees of freedom. This eliminates the need to associate a basis for the planes perpendicular to each edge; such a basis can not depend continuously upon the edge orientation. The finite element space is piecewise polynomial over the four tetrahedra formed by adding the circumcenter, and their traces on each fac...

Nowadays, with the advances of Finite Element Analysis (FEA) packages, some of the engineering and design problems such as stress or thermal deformation can be successfully solved. These are convenient for better incorporating the design constraints of various tasks such as injection molded parts, or rapid prototyping and tooling. Mesh generation is the major step of finite element method for n...

We describe a new finite element method for solving the Eul~r equations, and present the results of a transonic flow calculation for a commercial aircraft with py]on mounted engines. The finite element method uses a tetrahedral mesh, and establishes conservation of mass, momentum and energy in polyhedral control volumes by sulm~in~ fluxes through the faces of the t(~trahedra. The tetrahedra are...

New algorithms are proposed for the modification of a mixed hexahedra-tetrahedra element mesh to maintain compatibility by the insertion of pyramid elements. Several methods for generation of the p+yramidsare presented involving local tetrahedral transformations and’or node insertion near the he.titet interface. Local smoothing and topological operations improve the quality of the transition re...

We present a new shape measure for tetrahedral elements that is optimal in that it gives the distance of a tetrahedron from the set of inverted elements. This measure is constructed from the condition number of the linear transformation between a unit equilateral tetrahedron and any tetrahedron with positive volume. Using this shape measure, we formulate two optimization objective functions tha...

The goal is to generate tetrahedral decomposition of a general solid body, whose surface is given as a collection of triangular facets. The principle idea is that a vertex set in general positions guarantees existence of a unique triangulation which satisses the Delaunay empty-sphere property. (Algorithms for robust, parallel construction of such triangulations are available.) However, all of t...

Background: It was reported in a literature that approximately one third of the 4-cell stage embryos did not exhibit a tetrahedral shape. Non-tetrahedral embryos showed a lower in vitro developmental potential than tetrahedral embryos. Recently vitrification technology has been widely employed for embryo cryopreservation. The objective of this study was to prove our hypothesis that vitrified - ...

This paper presents an algorithm to extract adaptive and quality 3D meshes directly from volumetric imaging data primarily Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). The extracted tetrahedral and hexahedral meshes are extensively used in the Finite Element Method (FEM). Our comprehensive approach combines bilateral and anisotropic (feature specific) diffusion filtering, with...

Traditionally high-aspect ratio triangular/tetrahedral meshes are avoided by CFD researchers in the vicinity of a solid wall, as it is known to reduce the accuracy of gradient computations in those regions. Although for certain complex geometries, the use of highaspect ratio triangular/tetrahedral elements in the vicinity of a solid wall can be replaced by quadrilateral/prismatic elements, abil...