Defining the Grid

This task shows you how to Add, Merge, Split and Edit cells while defining the Grid.

Master stacking sequence mode is supported with no specific behavior, except the display of warnings when a mix of laminates (standard and defined from a master stacking sequence) is found, or when a laminate is incompatible with the master stacking sequence. In this case, the master stacking sequence and the layer data are not used downstream. This may occur when importing laminates on cells or after a manual edition of cells.

When importing grid data with a master stacking sequence, all the columns of the first line columns must be completed by # (or a number). Otherwise these columns will be ignored during the import.
See More about Materials and Laminates for more information.
 
  • This task is available in the CATIA Composites Engineering (CEG) product.
  • This task is available in the Composites Grid Design workbench.
Either work on the part where you have defined the Grid Panel or open the GridGA01.CATPart document.
  To define the laminate of the cell within the session, make sure you have defined at least materials as explained in Adding Materials
In GridGA01.CATPart, we have defined three materials and one laminate.






You must have defined the Grid Panel.
You can access the Grid definition dialog box either:
  • At its creation by clicking Grid   and selecting a Grid Panel,
  • Or by double-clicking an existing Grid or a cell of an existing Grid.
  • A warning is displayed if several structural elements have the same name.

As soon as cells are displayed in the 3D viewer, you can select them.

  • Multi-selection is available using the Ctrl key.
  • If you select cells in the 3D viewer, the corresponding lines in the dialog box are highlighted too.
  • When you select rows in the dialog box, the corresponding cells are highlighted in the 3D viewer.
  • Once laminate information has been added, all the cells that share the same laminate are displayed in the same color.

Starting the Grid Definition

  1. Click Grid   in the Grid Design toolbar and select GridPanel.1 as the Panel.
    The Grid Definition dialog box is displayed.
    Cells are created from the grid panel you have defined and displayed in the 3D viewer.

    The dialog box is updated:

    • The first column gives the rank of the item,
    • The second column gives the name of the cell,
    • In the Reference or Modified column, SS or TL indicates whether a stacking sequence
      or a thickness law has been defined.
    • The following columns give the name of the structural elements that define each cell.

  2. If required, select the Display label check box and click Options.
    In the dialog box that is displayed, you can select the information you want to display on the cells.

  3. Check the grid: Enter a threshold value for searching micro cells, and click Run.
    This check consists in finding:
    • Geometrically overlapping cells.
    • Micro-cells, that are cells with a surface lower than the threshold value.
      This threshold is given as a percentage of the largest cell found in the grid.

    As this check is time consuming, it is not done automatically.
    However, we recommend that you run it at the creation of the grid, or after a modification of the structure of the cells (add, split,...).
    The result of the check appears in a message. Detected cells are shown in the graphic area.

  4. Once you are satisfied with the grid definition (see steps below),
    click OK to validate and exit the dialog box.
    The grid is created in the specifications tree.
    Grid cells with two nodes as shown in the examples below are not created.
    or

Adding Cells

  1. Double-click Grid Panel.1.
    The Grid Definition dialog box is displayed.

  2. Highlight Added Group Group.3 in the dialog box. Select Parallel.1 in the specification tree and click Add.

    A Grid Reference Elements Group is added.

    Click OK to validate and exit the dialog box.
    If necessary, unhide Parallel.1.

  3. Revert to the Grid definition dialog box.
    Click Add in the dialog box.

    A dialog box is displayed.

  4. Select the reference elements that form the contour of the cell you want to add.
    Once those reference elements form a closed contour, a green tip replaces the red cross.

  5. Click OK. A message proposes you to edit the new cell.
    If you click Yes, go to Editing Cells.
    If you click No, a new cell is added to the grid, but without laminate information.

Merging Cells

  1. Select at least two cells, either in the dialog box or in the 3D viewer.
    Merge becomes available.

  2. Click Merge. The cells are merged into a single one.
    Only manifold cells can be merged.
    If the cells to merge do not have the same stacking sequence or the same thickness law,
    a message asks you to validate that the result cell will keep one of the laminates
    (the laminate with higher thickness is proposed).

Editing Cells

Edit lets you enter laminate information for a newly created cell or to overload the existing laminate information.

  1. Select one or several cells, either in the dialog box or in the 3D viewer, and click Edit.
    The cell definition dialog box is displayed.

  2. If you have selected one single cell, you can edit its name or its contour.

    • The name must be unique. If this is not the case, the creation is impossible and you are invited to change the name
    • When you edit the name:
      • the grid definition (dialog box and authoring window) is updated with this new name.
      • If it already exists, the virtual stacking (dialog box and authoring window) is updated with this new name.

    If you have selected several cells, their names and their contours are not editable.
    Only the number of selected cells is displayed.

     

  3. Click Cell contour definition.
    Select the reference elements that will make the new contour.
    Once this contour is valid, the red cross is replaced by a green check.

    Click OK to validate and revert to the Cell definition dialog box.

  4. Choose which version of the cells you want to modify, Reference or Modified.
    If you have done modifications in one version before switching to the other, a
     message informs you that those modifications will be lost.

  5. If you want to use a laminate already existing in your design, select it from the Laminate list.

  6. If you have not yet defined a laminate in your design, or if you want to define a new one,
    click New under Laminate.

    Define the laminate as explained in Adding Laminates.
    Click OK to validate and revert to the Cell Definition dialog box.
    This newly created laminate is stored under Composites Parameters > Laminates,
    and appears in the Composites Parameters dialog box, in the Laminates tab.

    and in the specifications tree

  7. If you want to apply the laminate from one cell to others

    • In the Grid Definition dialog box, select the cell with the desired laminate, and the other cells.
    • Click Edit.
    • Select the required laminate from the Laminate list.
    • Click OK. The laminate is applied to all the selected cells.

  8. Repeat the steps above as necessary.
    The dialog box is updated with the laminates information.

    The cells are displayed in the 3D viewer with the color of their laminate, when defined.
 

Exporting/Importing Grid Data

The .xls, .xlsx or .txt file must contain:

  • A table with the cell IDs,
  • The laminate name to apply to each given cell,
  • The list of the reference elements composing the contours of the cells,
  • The definition of each used laminate, with stacking defined either as stacking sequence or thickness law.

  1. Go to Import/export Management.

  2. Select the Version for which you want to export or import data (Reference or Modified).

  3. In Export to file, click ... and enter the path and name of the file where you want to export the data.
    In the File Selection box, select the format of that file (.xls, .xlsx or .txt).

  4. Click Export to launch the export.
    You can find examples of the export files in the Samples directory: GridData.xls, GridData.xlsx, GridData.txt.
    If all laminates are defined from a master stacking sequence, this specific format is used. Otherwise, export is done in the standard stacking sequence format, without layer key information. A warning is displayed.

    See More about Materials and Laminates for more information.

  5. Modify the export file according to your needs.
    In GridDataModified.txt, we have created a new laminate (Laminate.5) and applied it to Cells C18 to C23.

  6. In Import from file, click ... and enter the path and name of the file you want to import.

  7. Click Import to launch the import.
    A message informs you of the result of the import.
    The dialog box and the 3D viewer are updated with the imported data.


    Note that the new laminate is visible in the specifications tree, the Cell definition dialog box
    and the Composites Parameters dialog box after you have clicked OK in the Grid definition dialog box.
  • The name of the structural elements contained in the imported file must be the same as those used for defining the panel.
  • If two reference elements cut each other twice, an warning message is displayed.
 

Importing Data from the Virtual Stacking

When a Virtual Stacking has already been defined in your design,
you can import its laminate information in the grid.
Open GridGA02.CATPart from the samples directory.
 

  1. Double-click Grid.1.

  2. Select the Version for which you want to import the data. We have selected Modified.

  3. In Import from VS, select how the laminate information from the virtual stacking will be saved in the grid,
    as a SS (Stacking Sequence) or as a TL (Thickness Law).

  4. If several virtual stackings exist, click ... and select the one you need.

  5. Click Import.

  6. An information message is displayed, the dialog box and the cells in the 3D viewer are updated.
    The modifications are visible in the Cell definition dialog box once you have clicked OK
    in the Grid definition dialog box.
    Before the import:

    After the import:

 

Splitting Cells

  1. Select one or several cells to split, either in the dialog box or in the 3D viewer.

  2. Click Split and select the reference element that will split the cells.
    This reference element must intersect the cells only twice.
    If this is not the case, you have to perform the split in several steps, each complying with this rule.

  3. The cells are split.