“Continuum mechanics deals with idealized materials consisting of material points and material neighborhoods. It assumes that the material distribution, the stresses, and the strains within an infinitesimal material neighborhood of a typical particle (or a material element) can be regarded as essentially uniform. On the microscale, however, the infinitesimal material neighborhood, in general, is not uniform, consisting of various constituents with differing properties and shapes, i.e., an infinitesimal material element has its own complex and, in general, evolving microstructure. Hence, the stress and strain fields within the material element likewise are not uniform at the microscale level. One of the main objectives of micromechanics is to express in a systematic and rigorous manner the continuum quantities associated with an infinitesimal material neighborhood in terms of the parameters that characterize the microstructure and properties of the micro-constituents of the material neighborhood.” [From (1999, p. 11).]