Eur. Phys. J. E 7, 353-370 (2002)
DOI: 10.1140/epje/i2002-10011-7
Directed force chain networks and stress response in static granular materials
J.E.S. Socolar1, D.G. Schaeffer2 and P. Claudin31 Department of Physics and Center for Nonlinear and Complex Systems, Duke University, Durham, NC 27708, USA
2 Department of Mathematics and Center for Nonlinear and Complex Systems, Duke University, Durham, NC 27708, USA
3 Laboratoire des Milieux Désordonnés et Hétérogènes (UMR 7603), 4 place Jussieu, case 86, 75252 Paris Cedex 05, France
(Received 16 January 2002)
Abstract
A theory of stress fields in two-dimensional granular materials
based on directed force chain networks is presented. A general
Boltzmann equation for the densities of force chains in different
directions is proposed and a complete solution is obtained for a
special case in which chains lie along a discrete set of directions.
The analysis and results demonstrate the necessity of including
nonlinear terms in the Boltzmann equation. A line of nontrivial
fixed-point solutions is shown to govern the properties of large systems.
In the vicinity of a generic fixed point, the response to a
localized load shows a crossover from a single, centered peak at
intermediate depths to two propagating peaks at large depths that
broaden diffusively.
45.70.Cc - Static sandpiles; granular compaction.
83.80.Fg - Granular solids.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002