Experimental Test of  the "Isotropic" Approximation for Granular Materials using p=constant Compression


P. Evesque: Lab MSSM, UMR 8579 CNRS, Ecole Centrale Paris, 92295 Châtenay-Malabry, France, evesque@mssmat.ecp.fr


Abstract: Experimental data from axially symmetric compression test at constant mean pressure p=(s1+s2+s3)/3 on Hostun sand from Bouvard experiments are used to study the validity of an "isotropic" modelling as a function of density .The isotropic assumption is found to be quite good for loose samples and/or in the range of large pressure. For smaller mean pressure, anisotropic response is observed at few percents of axial deformation. Relation with anisotropic distribution of local force is made. 

Pacs # : 5.40 ; 45.70 ; 62.20 ; 83.70.Fn

poudres & grains 12 (1), 11-16 (février 2001)