Defining the Panel

• Defining the Grid Panel,
• Editing a Reference element group, i.e. defining default values that are applied to all the elements of that Reference element group,
• Editing Reference elements, i.e. defining values that will apply specifically to that Reference element.

• This task is available in the CATIA Composites Engineering (CEG) product.
• This task is available in the Composites Grid Design workbench.

• The last two options are not proposed if the reference element has not been created from a surface.
• You can edit the parameters of a Reference element group or a Reference element via a formula.
• When you edit a Reference element group, you apply the values of those parameters as formulas to all the reference elements of the group.
• Sub-staggering data will be taken into account when you will generate the plies.
• Centered ply drop under Clearance has been renamed Centered Ramp Support.

Defining the Grid Panel

1. Click Grid Panel  in the Grid Design toolbar.
   The Panel definition dialog box is displayed.
   
   A Grid definition node is created in the specification tree.
   
   A Grid Reference Elements Group is proposed in the dialog box and created in the specification tree.
   For the moment it is empty.
   Its default name is Grid Reference Elements Group.x.
   
   You can edit this name: Key in the required name in Group prefix and click Rename Group.

2. Select MOLD as the Support Surface.
   Note that holes are not allowed on the support surface.
   
   The Draping direction is displayed in the 3D viewer.
   If necessary, click Reverse direction in the dialog box,
   or click the red arrow in the 3D viewer to invert the Draping direction.
   

3. Select the Rosette from the list.
   See About Rosette and Rosette Transfer Type for more information.

4. Create one Reference element group with the Group prefix H:

   Select the grid Reference Elements Group.1 in the dialog box Optional: Enter H as the Group prefix, and click Rename Group. The name is updated. Select the elements in the 3D viewer. Reference elements (e.g. ribs and stingers) can be either: Curves Or surfaces or planes. The ramp support is previewed in the graphic area. A warning is displayed if several Reference elements have the same name. If a reference element is closed, it is split into 3 sub-elements with the same staggering information as the original reference element. A contextual menu is available to remove or replace a Reference element, as well as arrows to reorder them. If a Grid has been created, new cells can appear or others can be removed. In that case, the Stacking Areas Table, Sequence Shape even the Plies contours will be updated. If you edit an existing Grid Panel and you need to edit a Reference element group, select it in the dialog box to display the list of its elements.

5. They are added to the specification tree and to the dialog box:
   
   

6. A grid panel may contain several Reference element groups.
   Click Add in the Reference element groups frame.
   A new Reference element group is added both in the dialog box and in the specification tree.
   Enter V as the Group prefix and select the vertical planes.
   
   A contextual menu is available to remove Reference element groups.

8. Optional: Define the limits of the panel (i.e. the Edge of Part). They will show the part boundaries and its holes.
   Although Panel limits are known and can be defined early in the design while defining the Panel,
   designers often prefer to work without limiting the plies before having reached the stage
   where the design is almost finished and detailed.
   For this reason, the limit contour defined as Panel limits will actually limit the plies once you have activated it with the Limit plies from panel limits command.
   See Limit plies from panel limits.
   

   Click Add in the Panel limits frame. A contour is added in the dialog box. Select curves so that they form a closed contour. A green tip replaces the red cross. Use Insert After, Before and Remove to modify the order of the curves as well as the contour. Use the contextual menu to create the curves of the contour

It is visible in the dialog box when you re-open it:

• If you are editing an existing Grid Panel, this parameter is editable too.
• If you are editing an existing Grid Panel, and change the Side attribute of a limit contour,
  a warning message will be displayed as this will impact the ply.
• An arrow lets you decide of the limitation side of limit contours.
  
• You can define several Grid Panels in the same CATPart.

9. Click OK to validate and exit the dialog box.
   The Grid Panel is created in the specification tree:
   
   and in the 3D viewer:
   

Editing a Reference Elements Group

You can edit a reference elements group to select a default ramp definition.
This ramp definition is applied to elements already in the group, as well as to the elements you add in the future.

For more information, see Specifying a Ramp Definition.

1. To edit a reference elements group, either:

   Select it in the Panel definition dialog box and click Edit. Or, once it has been created, double-click it in the specification tree. Or, once it has been created, right-click it in the specification tree and select Definition.

2. Continue as explained below for a reference element with the difference that there is no sub-staggering.

3. At validation, if reference elements already existed in the group, select how to propagate the changes.

The defined values are stored as parameters under each element of the reference elements group.

Editing a Reference element

You can edit a specific staggering for a Reference element:
Reference elements can be divided into sub-elements, with specific staggering information that overrides the global information.
For a quick definition of the slope, contextual menus on elements in the graphic area provide direct change of the parameter values,
using values defined elsewhere in the Reference Element or the Grid Panel.
Modification applies on both sides, if applicable, or on selected side otherwise.
See also About Staggering Edition

1. To edit a Reference element either:

   Select it in the Panel definition dialog box, and click Edit Or, once it has been created, double-click it in the specification tree Or, once it has been created, right-click it in the specification tree and select Definition in the contextual menu. Geometry information (Surface and Geometry) is displayed but not editable.

2. Click Reverse Direction or the arrow in the work area to invert that staggering direction.

3. Specify default ramp definitions.

   Decide to have the same ramp definition on both sides or not. From the list of Side +, select the ramp definition to apply as default. Depending on the geometry, not all ramp definitions are proposed: Offset/Offset ramp definitions are not proposed if the input geometry is not a surface of a plane. Between two curves, Angle to curve and Custom ramp definitions are not proposed if the input curves are not on the same reference surface as the Grid Panel Surface. Alternatively, click New and specify a new ramp definition. Repeat on Side - if you have cleared Same on both sides option. Select the blank item in the list if you do not want to apply a ramp definition to the reference element.

4. Add a Sub-Staggering.
   The default ramp definition is proposed.
   

5. Check and manage the sub-staggerings.

   Select one sub-staggering in the table. It is highlighted in the work area. Check the information in the work area or in the table (Overlapping or adjacent sectors). Select two adjacent sub-staggering sectors (sharing a common reference element) and click Merge. Right-click an information tag to edit the staggering or replace it with one of the availabe ramp definitions.

6. Use the arrows to re-order selected sub-staggerings.

7. Select a sub-staggering and the two elements (Limit 1 and Limit 2) that relimit the sub-element.

   As you select the relimiting elements, they are highlighted in the work area. The sub-element is displayed in green in the work area.

8. Alternatively, in the graphic area, place the pointer over a valid reference element.
   
   Click the scissors that appear.
   Relimiting elements are automatically set, the sub-staggering is created.

9. Select a geometry to define the direction for Side +.
   A contextual menu is available.

10. Define how ramps are visualized in the work area.

    An arrow shows the orientation of the reference elements. Clearance and slope values are displayed. They are editable by their contextual menu. Side+ is identified by solid lines, Side- by dashed lines. These lines do not lie on the reference surface, but on a 3D plane tangent to the surface. As a consequence, they are sometimes distant from the corresponding ramp support curves. Sub-staggering sectors are identified in different colors. When the slope is defined by a ratio, the step is computed from the thickest material of the plies. Active staggering (the one selected from the list) is highlighted. The preview is automatically updated. Standard: Each ramp is visualized by 3 curves on each side. This is the only possible mode when no or more than one Virtual Stacking exists. Virtual Stacking Drops: The number of displayed curves varies with the number of plies dropped in Virtual Stacking. Combination of Both: Same as Virtual Stacking Drops, with a minimum of 3 curves displayed on each side. The curves are displayed in low intensity if no ply drop applies. Minimal

For more information, see About Staggering Edition.

11. When Virtual Stacking Drops is selected, select Drop plies with same layer level on same curve.
    The reference element visualization considers that plies with the same layer level are on the same curve.
    For example, plies generated as follows
    
    are visualized like this when the option is cleared.
    
    and like this when the option is selected
    
    We recommend you select this option when plies are generated with the option Drop plies same layer level on same curve.

The Sub-staggering information are taken into account while generating the ramp supports.