Vol.11, No2, 2011, pp. 63-74
UDC 666.971.4.019:519.6

INFINITESIMAL NON-LINEAR COSSERAT THEORY BASED ON THE GRAIN SIZE LENGTH SCALE

Hamidréza Ramézani1, Jena Jeong2

1) CRMD, UMR CNRS 6619- Research Center on Divided Materials, École Polytechnique de l'Université d'Orléans, France, hamidreza.ramezani@univ-orleans.fr

2) ESTP/IRC/LM-Lean Modeling-École Spéciale des Travaux Publics, du Bâtiment et de l'industrie (ESTP), Cachan cedex, France, jeong@profs.estp.fr

Abstract

A non-linear Cosserat theory involving the Arbitrary Lagrangian-Eulerian (ALE) method has been introduced into the brittle isotropic materials (amorphous glass and cement mortar) using the Modified Brazilian Disk (MBD) under an uni-axial compressive loading. These numerical experiments shed light on the nature of the Cosserat-based media and material moduli determination which are difficult to acquire using the most well-known experimental viewpoints. By using the identical micro-rotation constants (a = b = g = mLG2 and Y = 2/3), the Cosserat moduli reduce to only four constants for the 3D cases. According to the results obtained in this paper, the present methodology substantiates that the Cosserat theory would be readily applied to the wide range of materials from the full amorphous materials to the heterogeneous materials by changing the length scale parameter. Some fresh routes and new outlooks are discussed afterwards.

Keywords: non-linear Cosserat theory, 3D-FEM, grain size, Modified Brazilian Disk, characteristic length scale

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