Anisotropy in granular materials at different scales

This paper is dedicated to the analysis of the local phenomena which give rise to anisotropy in granular materials. This anisotropy can be observed for small strains (elastic strains) as well as large irreversible strains (plastic strains). Elastic anisotropy appears to be due to the distribution of contacts, the shape of particles and the non-linear local contact law. Anisotropic non-reversible behaviour seems to be related to two kinds of anisotropy, the usual geometric anisotropy and a static anisotropy governing the distribution of contact forces. (C) 2004 Elsevier Ltd. All rights reserved.