About Draping Direction and Reference Surface Consistency

Global Rules

A ply is consistent with its reference surface and draping direction when:

• The ply is an engineering ply (no skin swapping), and the reference surface of its contour and the draping direction of the ply are the same as those of the plies group.
• The ply is a manufacturing ply (hence with skin swapping), and follows the skin swapping rules below:
  • All plies of a given plies group are swapped on the same manufacturing surface.
  • The draping direction is consistent on all plies after swapping: All draping directions are along the normal to the manufacturing surface, or are all along the inverted normal.
  • Draping direction changes for the manufacturing surface do not impact the initial draping direction of plies group and plies on the engineering reference surface.

Reference Surface of Plies and Cut-Pieces

An information message is displayed in the following cases:

• The reference surface of a ply is not that of the plies group.
• All the plies of the plies group have the same reference surface, but not that of the plies group.
• The reference surface of the ply is the manufacturing surface, but some plies in the plies group are not manufacturing plies.
• The reference surface of the ply is a manufacturing surface, but not that of the other plies of the plies group.

Draping Direction

At its creation, the draping direction of a plies group applies to all the plies of the plies group. This direction is generally considered as the engineering draping direction. However, individual plies can be given a different draping direction, for example by manual edition.

Manufacturing plies can be created by skin swapping the engineering plies onto the manufacturing reference surface. You can invert the draping direction during skin swapping, which may result in inconsistency among the plies of a given plies group.

An information message is displayed in the following cases:

• Inconsistency in the draping direction of plies or cut-pieces without skin swapping: The draping direction of a ply is not that of the plies group.
• Inconsistency in the draping direction of plies or cut-pieces with skin swapping: The draping direction of a ply has been inverted during skin swapping, but that of all the other plies has not been inverted.

Input of Commands

A control is done on the stacking, plies group, sequence, plies, or cut-pieces used by commands as input.

• A panel lists the results of the control.
• The context menu of each line lets you perform a visual control of the elements.
• A visual feedback (highlight of contour and diagnosis text) helps you solve the problem.
• You are asked whether you want to continue or not.

See Enable draping direction and reference surface consistency checks on plies group option in Preferences for more information.

Warnings are displayed when:

• All the plies in the plies group have different reference surfaces.
• All the plies in the plies group have the same reference surface, but not that of the plies group.
• Some plies of the plies group have skin swapping, some have not.
• All the plies in the plies group are manufacturing plies, but with different reference surfaces.
• The plies in the plies group have different draping directions.
• All the plies in the plies group have been swapped, but with different draping directions.

For the Plies Group Update or Edition:

• Access to the Stacking Management is proposed to solve the problems. Use Multiple Rows Edition to edit the draping direction.
• When editing a plies group with skin swapping already performed, both the engineering and the manufacturing draping directions are displayed on their respective reference surface. When inconsistency is detected, the arrow of the manufacturing draping direction is replaced with a feedback.

A control is done in the following commands. An error is displayed when the inconsistency prevents the computation of the results. A warning is displayed when the inconsistency does not affect the command output.