Basically, the Composites geometry is made of one or several contours lying on a support surface, that defines the geometry of plies, zones, EOPs, etc... The capability to create a 2D shell from this geometry is a good sign that this geometry is valid.
Before to V5-6R2014 SP2:
- The 2D shell was created only by the commands that needed it, and stored as a datum under the plies and cut-pieces.
- In some cases, you were able to go on with your design even though a 2D shell could not be created from the geometry you had defined. The problem was detected late in the process, for example when computing iso-thickness areas.
- This datum 2D shell was deleted automatically when the Composites geometry was modified.
- You were also able to delete it manually using Remove Ply Shells in the contextual menu of the Composites objects.
Starting with V5-6R2014 SP2:
- The 2D shell is automatically created for all Composites geometries, as soon as possible in the process, ensuring a better quality and the early detection of problems.
- This 2D shell is created as a feature, and cannot be deleted. As a consequence, the Remove Ply Shells command is no longer available, except for old models.
- This 2D shell is neither visible nor pickable in the 3D viewer. However, if Highlight faces and edges is selected in the Tools > Options > Display > Navigation tab, the 2D shell is highlighted when you select a ply.
- When a problem is detected:
- A message is issued whenever the 2D shell cannot be created (typically when the contour defines disconnected areas, or contours intersect each others, etc.).
- In the Stacking Management, the Contour 3D column is marked KO.
- A ! mask is displayed in the specification tree on the invalid Composites geometry and its parent elements.
- The geometry parent elements can be edited from the message box, or by double-clicking the geometry in the specification tree.
Older existing models are not upgraded automatically to this new mode:
- Remove Ply Shells is still available for those models.
- To upgrade the older models:
- Either select all the Composites Geometry nodes in the specification tree, and select Selected objects > Upgrade in the contextual menu.
- Or right-click the stacking and select Stacking Object > Migrate to Automatic Shells.
- An update is requested with both methods.
