Jamming transition in a two-dimensional open granular pile with rolling resistance

  • Caio F. M. Magalhães Universidade Federal de Itajub\'a - Campus de Itabira, Rua Irm\~a Ivone Drumond, 200, 35900-000 Itabira, Brasil
  • Allbens P.F. Atman Departamento de Física e Matemática, Centro Federal de Educação Tecnológica de Minas Gerais -- CEFET-MG
  • Gaël Combe UJF-Grenoble 1, Grenoble-INP, CNRS UMR 5521, 3SR Lab. Grenoble F-38041, France
  • José G. Moreira Universidade Federal de Minas Gerais, Caixa Postal 702, 30161-970 Belo Horizonte, Brasil
Keywords: Granular piles, Jamming transition, Avalanches

Abstract

We present a molecular dynamics study of the jamming/unjamming transition in two-dimensional granular piles with open boundaries. The grains are modeled by viscoelastic forces, Coulomb friction and resistance to rolling. Two models for the rolling resistance interaction were assessed:  one considers a constant rolling friction coefficient, and the other one a strain dependent coefficient. The piles are grown on a finite size substrate and subsequently discharged through an orifice opened at the center of the substrate. Varying the orifice width and taking the final height of the pile after the discharge as the order parameter, one can devise a transition from a jammed regime (when the grain flux is always clogged by an arch) to a catastrophic regime, in which the pile is completely destroyed by an avalanche as large as the system size. A finite size analysis shows that there is a finite orifice width associated with the threshold for the unjamming transition, no matter the model used for the microscopic interactions. As expected, the value of this threshold width increases when rolling resistance is considered, and it depends on the model used for the rolling friction.

Received: 14 June 2014,  Accepted: 7 October 2014; Reviewed by: R. Arévalo, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore; Edited by: L. A. Pugnaloni; DOI: http://dx.doi.org/10.4279/PIP.060007

Cite as: C F M. Magalhaes, A P F Atman, G Combe, J G Moreira, Papers in Physics 6, 060007 (2014)