3D grid-reinforced smart composites with periodic or nearly periodic arrangement of inclusions which are the subject matter of this book are not only worth considering because of their practical uses in various fields but also due to the obvious advantages they have over other types of composites in being more amenable to analytical and numerical treatments. This book predicts effective properties of such structures for a wide range of geometrical and material parameters. Hence, comprehensive micro-mechanical approaches including analytical and numerical modeling have been developed. The analytical modeling is based on the Multi-scale Asymptotic Homogenization Method whereas the numerical modeling is based on Finite Element technique. The models presented in this monogram have adopted general anisotropy for its importance from the practical view-point; however, it renders the analysis more complex. The AHM transforms original Boundary Value Problems describing piezothermoelastic behavior of such structures into a simpler set of problems characterized by effective coefficients. The developed FE models have been used to compare results obtained by the two approaches using examples.