Force networks and the dynamic approach to jamming in sheared granular mediaG. Lois1, 2 and J. M. Carlson1
1 Department of Physics, University of California - Santa Barbara, CA 93106-9530, USA
2 Department of Physics, Department of Mechanical Engineering, Yale University - New Haven, CT 06520-8284, USA
received 25 June 2007; accepted in final form 2 October 2007; published December 2007
published online 23 October 2007
Diverging correlation lengths on either side of the jamming transition are used to formulate a rheological model of granular shear flow, based on the propagation of stress through force chain networks. The model predicts three distinct flow regimes, characterized by the shear rate dependence of the stress tensor, that have been observed in both simulations and experiments. The boundaries separating the flow regimes are quantitatively determined and testable. In the limit of jammed granular solids, the model predicts the observed anomalous scaling of the shear modulus and a new relation for the shear strain at yield.
81.05.Rm - Porous materials; granular materials.
83.80.Fg - Granular solids.
47.50.-d - Non-Newtonian fluid flows.
© Europhysics Letters Association 2007