Create Midmesh

Use the Midmesh: Automatic tool to automatically generate a mesh at the midplane location, directly from the input geometry (components, elements, solids or surfaces), without first creating a midsurface. This saves significant time over the traditional midsurface-based approach.

  1. From the 2D ribbon, click the Midmesh > Automatic tool.
    Figure 1.


  2. Optional: On the guide bar, click to define midmesh options.
  3. Select geometry.
    Use the drop down menu on the guide bar selector to choose components, elements, solids, or surfaces as the source geometry type.
  4. Edit the extraction size value in the microdialog.
  5. Click Midmesh in either the microdialog or the guide bar.
The midmesh is extracted as FE geometry. HyperMesh organizes the midmesh elements in the Midmesh.# component (the name is based on the Destination component option).

Options for Creating Midmesh

Access the following options by clicking on the Midmesh: Automatic tool guide bar.

Edit criteria
Set the minimum size and target element size settings in the criteria file to control the resulting midmesh via the Criteria File Editor.
Extraction size
The midmesh extraction element size. By default this is taken as the target element size from the criteria file. This can be set smaller than the target size, though that is not recommended unless there are problems extracting at the target size.
Minimum size
Minimum element size allowed in the finalized mesh. This in combination with the ‘suppress proximity edges factor’ and 'combine non-manifold edges factor’ can ensure that the output mesh is ready for rebuild with the same criteria.

Can only be modified in the Criteria File Editor.

Element Type
Select the output element type.
Mixed
Quad-dominant mesh.
Tria
Tria-only mesh.
Method
Select the method of midmesh extraction.
Casting
Generate midmesh optimized for casting parts. The casting method handles midmesh on complex, freeform surfaces and variations in thickness.
Extrusion
Perform midmesh extraction on extrusion parts. The extrusion method handles midmesh on linear and consistent cross-sectional profiles.
Mask input entities
Hide input midmeshed entities in the modeling window upon exiting the context.
Destination component
Select which component newly created midmeshes are placed in.
Ignore flat edges
Do not imprint flat edges from the input geometry onto the midmesh.
Figure 2. Option Off
Figure 3. Option On
Flatten connections
Aligns/flattens the midmesh at ribs/connections.
Figure 4. Option Off
Figure 5. Option On
Step offset mode
This option allows finer control of how stepped geometry (one side continuous surface, and opposite side steps) is captured. This option is valid only when flatten connections is enabled. Values can be:
Automatic – Steps of different thickness across a common base surface are automatically offset to a uniform distance from the base surface.
Middle everywhere – Each step will be placed in the middle everywhere.
Middle of thickest plate – All steps that share a common base are moved to the middle of the thickest step. This might place portions of the midmesh outside the solid.
Middle of thinnest plate – All steps that share a common base are moved to the middle of the thinnest step.
Figure 6.


Suppress proximity edges factor
The minimum size factor for removing edges within proximity. Edges closer than this factor times minimum size will be suppressed.
Figure 7. Option Off
Figure 8. Option On
Fillet treatment factor
The minimum size factor to remove small fillets. Fillets smaller than this factor times minimum size will be removed.
Figure 9. Option Off
Figure 10. Option On
Combine non-manifold edges factor
The minimum size factor for joining non-manifold edges. Non-manifold edges closer than this factor times minimum size will be combined.
Figure 11. Option Off
Figure 12. Option On
Defeature ribs width factor
The minimum size factor for removing small ribs. Ribs closer than this factor times minimum size will be suppressed. Default is 0.9.
Defeature openings with width <
The minimum size factor for removing small holes and openings.
Figure 13. Option Off
Figure 14. Option On