ABSTRACT
Although the word "micromechanics" may imply the study of mechanical behavior at the microscopic level to a materials scientist, it has evolved in the composite mechanics literature as a way of describing the physical behavior of constituent materials in a composite, the interaction of these materials, and the resulting behavior of the composite. In Fig. 1, the composite lamina, which is the basic building block of a composite structure, is the subject of the micromechanical analysis. On the other hand, macromechanics is concerned with the gross physical behavior of composite materials and structures (e.g., lamina, laminae, and structure in Fig. 1) without regard for the corresponding behavior or interaction of the constituents. The constituent material properties of interest in micromechanics are not necessarily determined at the microscopic level but are usually found by testing the fibers, matrix materials, and other constituents in the same manner as one would test the composite to determine the property of interest. For example, for the micromechanical prediction of a particular tensile modulus of elasticity of the composite lamina in Fig. 1, one would need the corresponding moduli of fiber and matrix materials, which are measured using tensile tests similar to that used in the measurement of the composite modulus. The terms "structureproperty relationships" and "effective modulus theories" are also used frequently in the literature for the same purpose [1-5].
