Crystals and polycrystals, composites and polymers, grids and multibar systems can be considered as examples of media with microstructure. A characteristic feature of all such models is the existence of scale parameters which are con nected with microgeometry or long-range interacting forces. As a result the cor responding theory must essentially be a nonlocal one. This treatment provides a systematic investigation of the effects of micro structure, inner degrees of freedom and non locality in elastic media. The prop agation of linear and nonlinear waves in dispersive media, static, deterministic and stochastic problems, and the theory of local defects and dislocations are considered in detail. Especial attention is paid to approximate models and lim iting transitions to classical elasticity. The book forms the second part of a revised and updated edition of the author's monograph published under the same title in Russian in 1975. The first part (Vol. 26 of Springer Series in Solid-State Sciences) presents a self contained theory of one-dimensional models. The theory of three-dimensional models is considered in this volume. I would like to thank E. Kroner and A. Seeger for supporting the idea of an English edition of my original Russian book. I am also grateful to E. Borie, H. Lotsch and H. Zorski who read the manuscript and offered many sugges tions. Houston, Texas Isaak A. Kunin January, 1983 Contents 1. Introduction ...

Crystals and polycrystals, composites and polymers, grids and multibar systems can be considered as examples of media with microstructure. A characteristic feature of all such models is the existence of scale parameters which are con­ nected with microgeometry or long-range interacting forces. As a result the cor­ responding theory must essentially be a nonlocal one. This treatment provides a systematic investigation of the effects of micro­ structure, inner degrees of freedom and non locality in elastic media. The prop­ agation of linear and nonlinear waves in dispersive media, static, deterministic and stochastic problems, and the theory of local defects and dislocations are considered in detail. Especial attention is paid to approximate models and lim­ iting transitions to classical elasticity. The book forms the second part of a revised and updated edition of the author's monograph published under the same title in Russian in 1975. The first part (Vol. 26 of Springer Series in Solid-State Sciences) presents a self­ contained theory of one-dimensional models. The theory of three-dimensional models is considered in this volume. I would like to thank E. Kroner and A. Seeger for supporting the idea of an English edition of my original Russian book. I am also grateful to E. Borie, H. Lotsch and H. Zorski who read the manuscript and offered many sugges­ tions. Houston, Texas Isaak A. Kunin January, 1983 Contents 1. Introduction ............................................ .

Crystals and polycrystals,composites and polymers, grids and multibar systems can be considered as examples of media with microstructure. A characteristic feature of all such models is the existence of scale parameters which are connected with micro geometry or long-range interacting forces. As a result the corresponding theory must essentially be a nonlocal one. The book is devoted to a systematic investigation of effects of microstructure, inner degrees of freedom and nonlocality in elastic media. The propagation of linear and nonlinear waves in dispersive media, static problems, and the theory of defects are considered in detail. Much attention is paid to approximate models and limiting tran sitions to classical elasticity. The book can be considered as a revised and updated edition of the author's book under the same title published in Russian in 1975. The frrst volume presents a self-con tained theory of one-dimensional models. The theory of three-dimensional models will be considered in a forthcoming volume. The author would like to thank H. Lotsch and H. Zorsky who read the manuscript and offered many suggestions.

The recently proposed, fully multi-scale theory of doublet mechanics offers unprecented opportunities to reconcile the discrete and continuum representations of solids while maintaining a simple analytical format and full compatibility with lattice dynamics and continuum mechanics. In this monograph, a self-contained account of the state of the art in doublet mechanics is presented. Novel results in the elastodynamics of microstructured media are reported, including the identification of a new class of dispersive surface waves, and the presentation of methods for the experimental determination of the essential microstructural parameters. The relationships between doublet mechanics, lattice dynamics, and continuum theories are examined, leading to the identification of the subject areas in which the use of doublet mechanics is most advantageous. These areas include the analysis of domains as diverse as micro-electro-mechanical systems (MEMS), granular and particulate media, nanotubes, and peptide arrays.