21-09-2013, 04:57 PM
A checklist for reviewing a tria mesh before tetra meshing it and tips for tetra meshing
Topic details:
You can use the following checklist to review the tria elements prior to creating a tetra mesh with them.
Doing so can help you avoid troubleshooting why HyperMesh (HM) cannot tetra mesh the volume(s). If
you are unsure how to perform each check, see the annotated checklist at the end of this tip/trick.
Scenarios causing free element edges and / or T-connections:
1. Internal partitions in the volume of tria elements. If these are required, split the model into separate
volumes and tetra mesh separately.
2. Duplicate meshes on a surface. If these meshes are different from each other, then they cannot be
detected by using the duplicate elements check. However, the T-connections check may outline the
boundary since the definition of a T-connection is any element edge connected to two or more
elements.
Tips for tetra meshing using HM:
1. When selecting the tria elements in the tetramesh panel, make sure to select only those elements
that make up the closed volume. To view the volume's interior, use the hidden line panel on the Post
page while in performance graphics mode. (Press F1 to go to this panel.) Use the fill plot and
cutting functionality. The cut plane can be dragged in the graphics area.
2. When the tetra mesher fails to mesh a part, the elements it was working on when it failed are
automatically saved to the HM user mark. Go to the mask panel to display the elements on the mark
and turn off the display for all other elements. In the mask panel, click elems and then click retrieve.
Click elems one more time and then click reverse. Finally, click mask . Only the elements saved to
the user mark are now displayed in the graphics area. Usually, the elements causing the mesher to
fail are attached to the elements on the user mark. Use the find panel on the Tool page or the Find
Attached macro on the QA macro menu page to identify the elements that are attached to the
displayed ones. Examine these elements and use the above checklist to determine why the mesher
failed.