ABSTRACT

Recall that a composite is formed by combining reinforcement plus matrix plus interface. Therefore, composite properties depend on the properties of these three constituents as well as the size, shape, orientation, and distribution of reinforcement. Regardless of the constituent properties, the geometry and arrangement of the reinforcement is the most critical characteristic, and is, therefore, used to classify composites into three categories based on the aspect ratio of the reinforcement l/d, where l is the length and d is the diameter:

1. l/d → ∞, the composite is classified as unidirectional (continuous fibers). 2. l/d ≈ 1, the composite is classified as particulate. 3. l/d ≤ 500, the composite is classified as short fiber.