Breadcrumb
Constraint Counting for Frictional Jamming
Thu 21 February 2013, 14:00
Silke Henkes
ESPCI, Paris
Organiser: Mark Woodhouse
ABSTRACT
While the frictionless jamming transition has been intensely studied in recent years, more realistic frictional packings are less well understood. In frictionless sphere packings, the transition is predicted by a simple mean-field constraint counting argument, the isostaticity argument. For frictional packings, a modified constraint counting argument, which includes slipping contacts at the Coulomb threshold, has had limited success in accounting for the transition. We propose that the frictional jamming transition is not mean field and is triggered by the nucleation of unstable regions, which are themselves dynamical objects due to the Coulomb criterion. We create frictional packings using MD simulations and test for rigidity percolation with the pebble game algorithm as well as identify the partition of the packing into rigid clusters. To understand the cluster dynamics, we apply quasi-static shear strain in Lees-Edwards boundary conditions.