2004/07/31 by Jacco H. Snoeijer, Thijs J. H. Vlugt, Wouter G. Ellenbroek +2
Earth and Planetary Sciences · Engineering · Materials Science · Physics and Astronomy · #Geology and Paleoclimatology Research #Granular flow and fluidized beds #Material Dynamics and Properties #cond-mat.dis-nn #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreve.70.061306
published as Phys. Rev. E 70, 061306 (2004) · 17 pages, 17 figures
arxiv created 2004/09/13 · openalex publication_date 2004/12/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
An ensemble approach for force networks in static granular packings is developed. The framework is based on the separation of packing and force scales, together with an a priori flat measure in the force phase space under the constraints that the contact forces are repulsive and balance on every particle. In this paper we will give a general formulation of this force network ensemble, and derive the general expression for the force distribution P(f). For small regular packings these probability densities are obtained in closed form, while for larger packings we present a systematic numerical analysis. Since technically the problem can be written as a noninvertible matrix problem (where the matrix is determined by the contact geometry), we study what happens if we perturb the packing matrix or replace it by a random matrix. The resulting P(f) 's differ significantly from those of normal packings, which touches upon the deep question of how network statistics is related to the underlying network structure. Overall, the ensemble formulation opens up a different perspective on force networks that is analytically accessible, and which may find applications beyond granular matter.