02.

A structural composite is a material system consisting of two or more phases on a macroscopic scale, whose mechanical performance and properties are designed to be superior to those of the constituent materials acting independently. One of the phases is usually discontinuous, stiffer, and stronger and is called the ‘matrix’. Sometimes, because of chemical interactions or other processing effects, an additional distinct phase called an ‘interphase’ exist between the reinforcement of the matrix. The properties of a composite material depend on the properties of the constituents, their geometry, and the distribution of the phases. One of the most important parameters is the volume fraction of reinforcement or fiber volume ratio. The distribution of the reinforcement determines the homogeneity or uniformity of the material system. The more non-uniform the reinforcement distribution, the more heterogeneous the material, and the higher the scatter in properties and probability of failure in the weakest areas. The geometry and orientation of the reinforcement affect the anisotropy of the system.