Sat, 26 Jul 2008 07:29:50 BST CiteULike: kdesmond's Chevoir http://www.citeulike.org/user/kdesmond/author/Chevoir CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/kdesmond/article/2747272 <i>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 72, No. 2. (2005)</i><br /><br />We study the plane shear flow of a dense assembly of dissipative disks using discrete simulation and prescribing the pressure and the shear rate. Those shear states are steady and uniform, and become intermittent in the quasistatic regime. In the limit of rigid grains, the shear state is determined by a single dimensionless number, called the inertial number I, which describes the ratio of inertial to pressure forces. Small values of I correspond to the quasistatic critical state of soil mechanics, while large values of I correspond to the fully collisional regime of kinetic theory. When I increases in the intermediate dense flow regime, we measure an approximately linear decrease of the solid fraction from the maximum packing value, and an approximately linear increase of the effective friction coefficient from the static internal friction value. From those dilatancy and friction laws, we deduce the constitutive law for dense granular flows, with a plastic Coulomb term and a viscous Bagnold term. The mechanical characteristics of the grains (restitution, friction, and elasticity) have a small influence in the dense flow regime. Finally, we show that the evolution of the relative velocity fluctuations and of the contact force anisotropy as a function of I provides a simple explanation of the friction law. Rheophysics of dense granular materials: Discrete simulation of plane shear flows Frédéric da Cruz Sacha Emam Michaël Prochnow Jean Roux Fran\ccois Chevoir doi:10.1103/PhysRevE.72.021309 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 72, No. 2. (2005) 2008-05-02T23:57:00-00:00 2005 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 72 2 APS granular_flow qual qualifier http://www.citeulike.org/user/kdesmond/article/2747217 <i>Comptes Rendus Physique, Vol. 3, No. 2. (2002), pp. 163-175.</i><br /><br />The behavior of dense assemblies of dry grains submitted to continuous shear deformation is still not well understood. Recently it has been the subject of several experiments and discrete particle simulations. For both confined and free surface geometries, we present the general features of such flows as well as grain-level information. We then describe the main rheological models and their predictions. To cite this article: O. Pouliquen, F. Chevoir, C. R. Physique 3 (2002) 163-175. Dense flows of dry granular material Olivier Pouliquen François Chevoir doi:10.1016/S1631-0705(02)01309-9 Comptes Rendus Physique, Vol. 3, No. 2. (2002), pp. 163-175. 2008-05-02T23:02:34-00:00 2002 Comptes Rendus Physique 3 2 163 175 granular_flow qualifier