Hex vs Tet Mesh Comparisons

Objective:

• Comparison of Hexahedral versus Tetrahedral meshing algorithms Orthopaedic applications

Progress:

• Currently evaluating open source tetrahedral meshing algorithms
  • VTK
    • Slivers exist in resulting mesh
  • Netgen
    • LGPL license
    • Issues have been found regarding invalid memory references
    • Does not always converge to a solution
    • Difficult to specify desired mesh density
  • Tetgen
    • Non commercial license. Commercial license can be purchased
    • Has been used for medical applications including heart, vertebral body, and head meshes

• Performed an initial comparison of hexahedral versus tetrahedral algorithms
  • Study included comparison of hexahedral and tetrahedral meshing tools
  • Evaluated the results based the following criteria
    • Time to generate the mesh
    • mesh quality
    • Results of a static load analysis versus the number of elements

To Do:

• Evaluate other tetrahedral meshing algorithms
• Complete comparison study of hexahedral and tetrahedral tools.
• Direct conversion of hexahedral meshes into tetrahedral meshes using VTK

Key Investigators:

• Iowa: Nicole DeVries, Nicole Grosland, Vincent Magnotta

Links:

• Musculoskeletal Imaging, Modeling and Experimentation (MIMX)

Images:

The von Mises stress distribution for the various meshing techniques: IA-FEMesh (a) hexahedral mesh, (b) NETGEN tetrahedral mesh, and PATRAN (c) hexahedral mesh, (d) tetrahedral mesh with average element length of 1mm, and (e) tetrahedral mesh with average element length of 2mm.