The ply definition can be organized into Modeling Groups. These Groups do not affect the ply-ordering and definition, but they provide a way for you to better organize Composite Definitions and streamline your workflow. For example, you might choose to define one Ply Group for each substructure of a boat project- one for the hull, one for the deck, and one for the bulkhead.

Before working with a Modeling Group, you must specify an Oriented Selection Set and a Material (Fabric, Stackup, or Sublaminate). Within a Modeling Group, plies can be created. The lay-up is defined as it would be in production. The first ply is also first in the stacking sequence. The lay-up can be tailored by specifying the Orientation, Layering, geometrical Selection Rules, Draping Settings, and Edge Tapering for each ply.

A lay-up can also include an Interface Layer for carrying out a fracture analysis of a composite solid model in Mechanical. The interface layer is a separation layer in the stacking sequence, used to analyze the crack growth of existing cracks. The crack topology is defined with an interface layer in ACP while all other fracture settings are specified in Mechanical. The interface layers are exported as INTER204 or INTER205 elements and can be used to set up a Cohesive Zone Model (CZM) or a Virtual Crack Closure Technique (VCCT) analysis. They can also be used to define contacts zones between two layers. For more information, see Interface Delamination and Contact Debonding in the Mechanical User's Guide.

Lay-ups can also be defined or changed using the Excel Link interface. Changes can also be made by importing or exporting the lay-up as a CSV file.