What is the difference between a lamina and a laminate in composite materials?

What is the difference between a lamina and a laminate in composite materials?

• A. A lamina is a single ply with a given fiber orientation; a laminate is a stack of laminae bonded together with a prescribed stacking sequence.
• B. A lamina is a glass fiber sheet; a laminate is a carbon fiber sheet.
• C. A lamina is a resin-rich layer; a laminate is the fiber-rich layer.
• D. A lamina is the laminate's mid-plane; a laminate is the entire thickness.

Answer: (A)

In composites, a lamina is a single ply with fibers aligned in a chosen direction within a resin matrix. A laminate is the whole stack of those laminae bonded together in a prescribed sequence, where the orientation and order of each layer determine the overall stiffness and strength of the part. The idea is that the individual lamina provides its directional properties, and the laminate combines many such layers to tailor performance. The other statements don’t fit because the definition is about layers and their orientation, not the material type of the sheet, nor about resin- or fiber-rich regions, and the mid-plane is a geometric concept of the whole stack, not a single lamina.

In composites, a lamina is a single ply with fibers aligned in a chosen direction within a resin matrix. A laminate is the whole stack of those laminae bonded together in a prescribed sequence, where the orientation and order of each layer determine the overall stiffness and strength of the part. The idea is that the individual lamina provides its directional properties, and the laminate combines many such layers to tailor performance.

The other statements don’t fit because the definition is about layers and their orientation, not the material type of the sheet, nor about resin- or fiber-rich regions, and the mid-plane is a geometric concept of the whole stack, not a single lamina.