Laminates & Sandwiches
Advanced composite parts are produced using successive layers of fabrics. Each layer is referred to as a “ply”, multiple plies of resin-impregnated fabric strongly consolidated create a “laminate”.
An attribute of this unified laminate composite structure is that the orientation, number, type and location of the fibers can be arranged to control and optimize the directional strength and other properties of the composite.
The result is a unified anisotropic material with specific and unique characteristics not achievable with metals or similar isotropic materials which have uniform characteristics throughout their structure.
Although very lightweight, a single layer or ply of composite is usually too flexible for most practical applications. As with other materials, the thicker the laminate, the less flexible it becomes.
(the laminate properties are mainly dependent on a combination of the following items)
• The adhesive properties of the matrix system bonding the fibers and layers together.
• The fiber type used within each layer.
• The geometry or fiber angle in each layer.
• The ratio between matrix and reinforcement.
• The cure temperature.
• The compression pressure during the cure process.
SANDWICH PANEL is
Sandwich construction is a process in which is produced a “sandwich” of a lightweight, low density core material bonded between two skins of a laminate such as carbon fiber, fiberglass or aramid / kevlar. The cores are available in a wide range of materials, including honeycomb, different types of foams, and lightweight woods, such as balsa.
Engineering theory shows that the flexural stiffness of any panel is proportional to the cube of its thickness.
This use of separating the structural skins with a core material offers greater strength properties than that of the skins alone. By increasing the core thickness, is possible to increase the stiffness of the sandwich without substantially increasing weight and cost.