Mesh Topology Check

To check mesh entities topology

  1. On the Command Panel, click on Mesh.
  2. Click on Hex, Tet, Quad, Tri or Edge.
  3. Click on the Quality action button.
  4. Select Topology Check from the drop-down menu.
  5. Enter the appropriate value. This can also be done using the Pick Widget function.
  6. Click Apply.

Quality Check Topology [[Hex <range>] [Tet <range>] [Face <range>] [Tri <range>]]

If no entity list is given, it will check the entire model. Multiple element types are also allowed. The command checks for non-manifold boundaries (edges) in the element set entered. For quads and tris the command lists and highlights all edges that have more than two tris or faces connected.

Figure 1. Topology check for quads and tris

For hexes and tets it looks for edges with two or more elements connected that do not share common faces.

Figure 2. Topology check for hexes and tets

 

Additional topology checks fall into three categories:

Model Edge Check

The model edge check will find edges with adjoining quadrilaterals or triangles whose angles between the surface normals exceed a specified value. The default angle is 40 degrees.

The following commands check for model edges:

To check for model edges on volumes, surfaces and groups

  1. On the Command Panel, click on Mesh.
  2. Click on Volume, Surface or Group.
  3. Click on the Quality action button.
  4. Select Model Edge Check from the drop-down menu.
  5. Enter the appropriate values for Volume ID(s), Surface ID(s) or Group ID(s). This can also be done using the Pick Widget function.
  6. Enter the appropriate settings.
  7. Click Apply.

Topology check model edge {group|volume|surface|curve} <id_range> [angle <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

To check for model edges on blocks, sidesets and nodesets

  1. On the Command Panel, click on Analysis Groups and Materials.
  2. Click on Nodeset, Sideset or Block.
  3. Click on the Manage action button.
  4. Select Model Edge Check from the drop-down menu.
  5. Enter the appropriate values for Nodeset ID(s), Sideset ID(s) or Block ID(s). This can also be done using the Pick Widget function.
  6. Enter the appropriate settings.
  7. Click Apply.

Topology check model edge {block|sideset|nodeset} <id_range> [angle <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

To check for model edges on hexes, tets, quads/faces, tris or edges

  1. On the Command Panel, click on Mesh.
  2. Click on Hex, Tet, Quad, Trior Edge.
  3. Click on the Quality action button.
  4. Select Model Edge Check from the drop-down menu.
  5. Enter the appropriate values for Hex ID(s), Tet ID(s), Quad ID(s), Tri ID(s)or Edge ID(s). This can also be done using the Pick Widget function.
  6. Enter the appropriate settings.
  7. Click Apply.

Topology check model edge {hex|tet|face|tri|edge} <id_range> [angle <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

The optional angle parameter allows the user to specify a custom angle value against which the check will be performed. The default angle is 40 degrees.

By default, the command will draw the model edges.

By default, very little information is output to the command line. The optional verbose parameter will output a list of the flagged model edges.

By default, the model edges will be written to the group ‘model_edges’. Optionally, the user may specify no grouping, or the user may specify the name or id of an existing group into which the model edges will be written. The contents of the existing group will be replaced by the model edges.

Interface Checks

Trelis will verify the interfaces between sections of a model. The existence of coincident nodes, for example, may not necessarily be an error in the model if the nodes are in sliding contact or are constrained by some type of multi-point constraint.  The existence of coincident quadrilaterals or triangles may indicate that the model is not correctly joined.

To check for coincident nodes.

  1. On the Command Panel, click on Mesh and then Node.
  2. Click on the Quality action button.
  3. Select Coincidence Chenck from the drop-down menu.
  4. Select Coincident Nodes, Coincident Quadrilaterals/Faces or Coincident Triangles.
  5. Enter the appropriate settings.
  6. Click Apply.

Topology check coincident node {group|volume|surface|curve|vertex} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident node {block|sideset|nodeset} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident node {hex|tet|face|tri|edge|node} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

The optional tolerance parameter allows the user to specify a custom tolerance value against which the check will be performed. The default tolerance is 1.0 e-6.

The default group name is ‘coincident_nodes.’

All other options behave similarly to those described above under Model Edge Check.

To check for coincident quadrilaterals.

  1. On the Command Panel, click on Mesh and then Quad.
  2. Click on the Quality action button.
  3. Select Coincidence Chenck from the drop-down menu.
  4. Select Coincident Nodes, Coincident Quadrilaterals/Faces or Coincident Triangles.
  5. Enter the appropriate settings.
  6. Click Apply.

Topology check coincident quad {group|volume|surface} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident quad {block|sideset|nodeset} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident quad {hex|tet|face} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

The default group name is ‘coincident_quads.’

All other optional parameters behave similarly to those described above.

To check for coincident triangles.

  1. On the Command Panel, click on Mesh and then Tri.
  2. Click on the Quality action button.
  3. Select Coincidence Chenck from the drop-down menu.
  4. Select Coincident Nodes, Coincident Quadrilaterals/Faces or Coincident Triangles.
  5. Enter the appropriate settings.
  6. Click Apply.

Topology check coincident tri {group|volume|surface} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident tri {block|sideset|nodeset} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

Topology check coincident tri {hex|tet|face|tri} <id_range> [tolerance <value>] DRAW|nodraw|highlight] [BRIEF|verbose] [RESULT GROUP[{<name>|{<id>}|nogroup]

The default group name is ‘coincident_tris.’

All other optional parameters behave similarly to those described above.