title: Stress correlations in granular materials: an entropic formulation.
abstract: We study the response of dry granular materials to external stress using experiment, simulation, and theory. We derive a Ginzburg-Landau functional that enforces mechanical stability and positivity of contact forces. In this framework, the elastic moduli depend only on the applied stress. A combination of this feature and the positivity constraint leads to stress correlations whose shape and magnitude are extremely sensitive to the nature of the applied stress. The predictions from the theory describe the stress correlations for both simulations and experiments semiquantitatively.
authors.affiliation: Department of Mechanical Engineering, Yale University, New Haven, Connecticut 06520-8284, USA.
authors.forename: G
authors.initials: G
authors.lastname: Lois
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: T S
authors.initials: TS
authors.lastname: Majmudar
authors.forename: S
authors.initials: S
authors.lastname: Henkes
authors.forename: B
authors.initials: B
authors.lastname: Chakraborty
authors.forename: C S
authors.initials: CS
authors.lastname: O'Hern
authors.forename: R P
authors.initials: RP
authors.lastname: Behringer
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003198:Computer Simulation; D019277:Entropy; D008956:Models, Chemical; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: D003102:Colloids