Use Continuous Meshing with caution

[John_Holtz]

The option "Continuous meshing" on the mesh settings is intended to be used with shell elements. It's purpose is to connect the edges of one shell to the edge of the adjacent shell. (In other words, the mesh matches between faces. The loads are transferred directly from element to element without the need to use contact to bond the faces together.)

There are issues with the continuous meshing option when anything is applied to an edge of a shell. This includes loads, constraints, rigid connectors, bolt connectors, contact, and so on. Depending on the version of Inventor Nastran you use, the item applied to the edge can be applied to additional edges of the model during the analysis, or it can be applied to only some (or none) of the nodes on the selected edges. For example, extra load can be applied to the model, or some of the load may be missing.

If you have used continuous meshing, check the results carefully to look for potential problems with the results.

Here are some alternatives to using continuous meshing:

• If the model is a single part surface model that has only one surface body, you do not need to use continuous meshing. The single body meshes as one continuous piece (regardless of how many faces the single body has).
• If the model is a single part surface that has multiple surface bodies, use the "3D Model > Surface > Stitch" command to join the surfaces into one surface body. (I am not sure what this does to any split faces. Those may need to be re-done after stitching the surfaces.)

• If the model cannot be stitched, use "Contacts > Solver" . Set the Contact Type to offset bonded. (Offset bonded is used to create a moment connection which is generally what is used for a shell-to-shell connection. Bonded contact only transmits forces, not forces and moment.) The maximum activation distance should be slightly larger than the gap between the edges but no larger than half the mesh size.

Here are some articles on the Autodesk Knowledge Network (knowledge.autodesk.com) that are related to these items:

• Does Nastran In-CAD have continuous meshing of solid elements?
• Rigid connector applied to edge of shell is missing some nodes in Nastran (2019.2 and newer)
• Load applied to edge of shell is missing from analysis in Nastran (2019.2 and newer)
• Results indicate that constraints and loads are applied to extra edges in Nastran InCAD (2019.1 and older)
• Understanding maximum activation distance and contact type in a Simulation
• How to improve the continuous meshing process in Inventor Nastran

[g.ceruti]

hi @John_Holtz, 

can you detail which Inventor Nastran versions are involved with this issue?

[Roelof.Feijen · Accepted solution]

Another way to create a successful mesh if stitching cannot be used and you don't want to use the Solver Contact. 

Note that split is essential in this case (video) and you need to delete all the features after using the Copy Object command. Otherwise you will end up with a double layer of faces.

[arashS6VPN]

Hello

I have tried it but unfortunately it did not work.