title: Rheology of weakly vibrated granular media.
abstract: We probe the rheology of weakly vibrated granular flows as function of flow rate, vibration strength, and pressure by performing experiments in a vertically vibrated split-bottom shear cell. For slow flows, we establish the existence of a vibration-dominated granular flow regime, where the driving stresses smoothly vanish as the driving rate is diminished. We distinguish three qualitatively different vibration-dominated rheologies, most strikingly a regime where the shear stresses no longer are proportional to the pressure.
authors.affiliation: Kamerlingh Onnes Lab, Universiteit Leiden, Postbus 9504, 2300 RA Leiden, The Netherlands.
authors.forename: Geert H
authors.initials: GH
authors.lastname: Wortel
authors.affiliation: Kamerlingh Onnes Lab, Universiteit Leiden, Postbus 9504, 2300 RA Leiden, The Netherlands and Department of Physics, Duke University, Science Drive, Durham, North Carolina 27708-0305, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Dijksman
authors.affiliation: Kamerlingh Onnes Lab, Universiteit Leiden, Postbus 9504, 2300 RA Leiden, The Netherlands.
authors.forename: Martin
authors.initials: M
authors.lastname: van Hecke