ABSTRACT
Composite materials are those that consist of two or more constituent materials that together produce desirable properties for a given application. The traditional mixture of sand and cementing materials and reinforced steel bars embedded in concrete provide familiar examples of composite materials. Fiber–reinforced composite materials are the most commonly used modern composite materials that consist of high strength and high modulus fibers in a matrix material. In these composites, fibers are the principal load–carrying members, and the matrix material keeps the fibers together, acts as a load–transfer medium between fibers, and protects fibers from being exposed to environment (e.g., moisture, humidity, etc.). It is known that fibers are stiffer and stronger than the same material in bulk form, whereas matrix materials have their usual bulk–form properties. Geometrically, fibers have near crystal–sized diameter and a very high length–to–diameter ratio. Short fibers, called whiskers, paradoxically exhibit better properties than long fibers. Long fibers are used in straight form or woven form.
