Laminates

Laminate entities define the list of stacked plies which make up a laminated structure.

Laminate Types and Options

Additional options include control of symmetry so that only half of the plies need to be created (all solvers) and analysis methodology which manipulates how the ABD matrix is calculated (OptiStruct only).

There are three types of laminates:

Ply Laminates: Used to model parts which do not have T junctions. Typical examples are flat or curved panels.
Sublaminates: Used to model portions of a part with complex geometry like T junctions. Examples are the caps and webs of an I-beam.
Interface Laminates: Used to join the sublaminates of a part with complex geometry.

The items in the following table comprise laminate data.

Option	Description
Name	Name of the laminate.
Card Image	STACK if user profile is OptiStruct. /STACK if user profile is Radioss. None for other solvers.
Type	Controls laminate symmetry. Additionally, manipulates laminate ABD calculations (OptiStruct only). Total All plies must be specified, and all stiffness terms are developed. Membrane All plies must be specified, but only membrane terms are developed. Bending All plies must be specified, but only bending terms are developed. Smear Effects of stacking sequence are removed by setting B = 0 and D = [A]*(T^2)/12. Smear Core The last ply in the stack specifies the core. Plies above specify the face sheet. Stiffness of the core is ignored. Stiffness of the face sheet is calculated using the Smear calculations described above. Half the thickness of the face sheet is placed above the core and half is placed on the bottom to produce a symmetric laminate. Symmetric Only plies on the bottom half of the composite lay-up need to be specified. These plies are automatically symmetrically reflected to the top half of the composite and given consecutive numbers from bottom to top. Symmetric Membrane Only plies on the bottom half of the stack need to be specified. Only membrane terms for the full laminate are developed. Symmetric Bending Only plies on the bottom half of the stack need to be specified. Only bending terms for the full laminate are developed. Symmetric Smear Only plies on the bottom half of the stack need to be specified. Stiffness is then calculated using the Smear calculations described above.
NRPT	Number of repeats for plies in laminate.