Eur. Phys. J. E 2, 181-189
Dilatancy and friction in sheared granular media
F. Lacombe - S. Zapperi - H.J. Herrmann
PMMH-ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 05, France
lacombe@manet.pmmh.espci.fr
Received 16 November 1999
Abstract
We introduce a simple model to describe the frictional properties of
granular media under shear. We model the friction force in terms of
the horizontal velocity 
and the vertical position z of
the slider, interpreting z as a constitutive variable
characterizing the contact. Dilatancy is shown to play an essential
role in the dynamics, inducing a stick-slip instability at low
velocity. We compute the phase diagram, analyze numerically the
model for a wide range of parameters and compare our results with
experiments on dry and wet granular media, obtaining a good
agreement. In particular, we reproduce the hysteretic velocity
dependence of the frictional force.
PACS
81.40.Pq Friction, lubrication, and wear
- 83.20.Bg Macroscopic (phenomenological) theories
- 83.70.Fn Granular solids
Copyright EDP Sciences, Società Italiana di Fisica, Springer-Verlag
