Ply entities define composite lamina.

Ply entities are designed to be a simulation representation of a physical ply. To enforce this relationship, a ply entity can be stacked only once in a laminate – the same ply cannot appear multiple times in one or more laminates.

Physical plies manufacture laminates which make up composite structures. A physical ply has attributes of:
  • Material and thickness
  • Fiber orientation
  • Shape – any complex flat pattern that can be cut from a roll of material

Similarly, an FEA ply is composed of the same data attributes. The modeling process using ply entities should be thought of as analogous to working with a physical ply in manufacturing.

The items in the following table comprise ply entity data.
Option Description
Name Name of the ply. For solvers which use global names to connect layers from zone to zone, this will also be the name used upon realization.
Card Image PLY if user profile is OptiStruct. /PLY if user profile is Radioss. None for other solvers.
Thickness Ply thickness.
Orientation Fiber orientation. Rotation is applied from the defined material orientation.
Material Material entity assigned to ply.
Drape Draping result (OptiStruct, Radioss, Nastran, ANSYS, LS-DYNA) - contains additional corrections to ply thickness and orientation.

Draping result (Abaqus) – *DISTRIBUTIONS which contain thicknesses and orientations which supersede ply thickness and orientation.

FiberSim import – contain thickness and orientation corrections due to draping and FiberSim discretization of geometry which is used to generate ply shapes in HyperMesh.

Shape Shape of the ply. Can be defined by:
  • FEA – elements or element sets
  • Geometry – lines, surfaces or solids. Before analysis, requires ply realization to convert to FEA shapes.
Ply System Optional method to specify reference material orientation for specific ply. Supersedes material orientation defined on elements/properties as direction ply orientation is rotated from. Typically used when importing external composite models.
List of Base Surfaces Represent tooling surface of ply. Surfaces containing elements on which to extract FEA shapes during ply realization. Typically only used when importing external composite data.
Dummy Ply Used to specify number of layered solid elements generated in shell to solid conversion. Its placement in a laminate also organizes the plies in each solid layer. For example, a laminate with a stacking sequence of [ply1/ply2/dummy ply/ply3/ply4] would generate 2 layered solid elements.
Integration Points Abaqus, Radioss, LS-DYNA
TAMNUF (OptiStruct only) – Manufactured ply thickness which is used as step during composite size optimization. Optimization results will be n*TAMNUF so a discrete number of plies can be extracted.