Meshing a model in 3D

In this task, you will complete the following steps.

After you have generated a 3D mesh from a Dual Domain meshed model, you will move a selection of elements to a new layer and reveal the tetrahedral elements in the interior of the part. This involves the following steps:
  • Creating the new layer on which the selection will be placed
  • Ensuring this new layer is active
  • Selecting the elements to be isolated
  • Assigning these elements to the new layer
  1. Ensure the Mesh tutorial project you used in the previous task is open.
  2. Click Import, Home tab (Home tab > Import panel > Import).
  3. Navigate to the Tutorial folder, typically C:\Program Files\Autodesk\Simulation Moldflow Insight 20xx\tutorial.
  4. In the Files of Type drop-down list, select Study Files (*.sdy) .
  5. Select manifold_3d.sdy and click Open. Note that the mesh type is Dual Domain Mesh. Note the number of elements in the model.
  6. Click Mesh, Home tab (Home tab > Create panel > Mesh), to open the Mesh tab.
  7. Click Mesh Statistics, Mesh tab (Mesh tab > Mesh Diagnostics panel > Mesh Statistics). Note that there are no faults with the mesh. The Mesh Match ratio is lower than the recommended value because the geometry of the part has prevented opposite surfaces from aligning. The mesh match ratio is not important for a Dual Domain mesh that will be converted to a 3D mesh. Nothing needs to be done. However, a low mesh match ratio is one sign that the model may not be appropriate for Dual Domain analysis technology and would be best analyzed using a 3D mesh.
  8. Click Close when you have finished reviewing the mesh statistics.
  9. In the Study Tasks pane, right-click Dual Domain Mesh and select Set Mesh Type > 3D.
  10. In the Study Tasks pane, double-click 3D Mesh. The Generate Mesh dialog appears.
  11. A default value for the Global edge length has been allocated. Click the Tetra tab to display further meshing options for creating tetrahedral elements. The default value for the Minimum number of elements through thickness is 6.
    Note: Default values for the Global edge length and the Minimum number of elements through the thickness are usually adequate. If the Minimum number of elements through thickness value is increased, typically the Global edge length value should be decreased.
  12. Check the Remesh already meshed parts of the model option.
  13. Click Mesh Now. Close the message dialogs that appear before and after the meshing operation.
    Note: Since creating a tetrahedral (tetra) mesh is more complex than creating other types of mesh, it takes longer to produce. To obtain good 3D mesh results, it is essential to correct any defects there may be in the Dual Domain mesh before proceeding to create the 3D mesh.
  14. Click Mesh Statistics, Mesh tab (Mesh tab > Mesh Diagnostics panel > Mesh Statistics). The element count for the tetrahedral (3D) mesh is considerably higher than for the precursor Dual Domain mesh. This is because the 3D mesh has elements through the thickness of the part.
  15. Click Close in the Mesh Statistics dialog. After remeshing, it is important to recheck the mesh.
  16. Click Mesh Repair Wizard, Mesh tab (Mesh tab > Mesh Repair panel > Mesh Repair Wizard). The Items to check pane shows the diagnostics that can be run for a 3D mesh. It is recommended that all options be checked.
  17. Click Next to display an overview of the mesh.
  18. Continue to click Next to proceed to the next step. If there are errors in each step, click Fix as often as necessary to repair the errors. The balance of the diagnostics are within the specified limits. The Summary page outlines the number and type of modifications made.
  19. Click Close to exit the wizard.

    You can view aspects of the model by either introducing a cutting plane or by isolating a selected section onto a layer and then viewing the result.

  20. Enter -100 -165 2 in the Rotation Angle, View tab Rotation Angles text box (View tab > Viewpoint panel > Rotation Angle) and press Enter on your keyboard. This orients the model to a predetermined angle. Each number represents the angle to which the model has been rotated around the X axis, Y axis and Z axis respectively. The angle a model is rotated to is represented by the three numbers in the lower right hand corner of the Model pane. This feature is useful when you need to return to a specific view of a model.
  21. Click Edit, View tab (View tab > Cutting Plane panel > Edit), and click New on the Cutting Planes dialog. A cutting plane is created and the Move Cutting Plane dialog appears.
  22. Deselect Show active plane in the Move Cutting Plane dialog.
  23. Click and drag the cursor up and down the in the Model pane to move the cutting plane. The cutting plane appears to cut away the model, allowing you to see inside. The model looks hollow as only the surface facets of the tetrahedral elements are displayed by default.
  24. Close the Move Cutting Plane dialog, then click Edit, View tabEdit again, and deselect the cutting plane you just created.
  25. In the Layers pane, click New Layer. At the bottom of the Layers Panel list, a New Layer has been added.
  26. Uncheck this layer so that the elements placed on it will be hidden. The new layer is still highlighted in blue. This indicates that the layer is still active.
  27. Click Select, View tab (View tab > Navigate panel > Select), and then select a group of elements in a corner of the model.
  28. On the Layers pane, click Assign Layer. The selected elements are assigned to the active layer. Because the layer is hidden, the elements no longer appear in the Model pane. They could be retrieved at any stage by making the new layer active.
  29. Click Zoom Window, View tab Zoom Window and zoom in on the corner area where you have hidden elements.
  30. Click Center, View tab Center and pick a point in the center of the exposed area.
  31. Click Orbit, View tab Orbit and rotate the model or zoom in and out to examine the internal geometry.
    Note:
    • The elements within the model are visible when using this method, whereas the model appeared hollow when using a cutting plane.
    • At least 6 layers of elements through the thickness of the model are visible, as specified in the Mesh Generation dialog.
  32. Click Application Menu, and select (Close > Project) from the drop-down menu. Save the study if you are prompted to do so.

Click the Next topic link below to move on to the next task of the tutorial.