Dresden 2014 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 22: Slow Dynamics in Glasses and Granular Matter I (Joint Focus Session with DY and CPP)
DF 22.4: Vortrag
Donnerstag, 3. April 2014, 10:45–11:00, HÜL 186
Jamming of Frictional Particles: a First Order Phase Transition — •Matthias Grob1, Claus Heussinger2, and Annette Zippelius1,2 — 1Max-Planck-Institut für Dynamik und Selbstorganisation, Göttingen, Deutschland — 2Institut für Theoretische Physik, Universität Göttingen, Göttingen, Deutschland
With numerical simulations, we produce flow curves for dense frictional granular media with features different from the frictionless analog. When the strain rate is controlled and increased, a smooth transition from inertial to plastic flow is observed below a critical volume fraction. Above this packing fraction, the transition becomes discontinuous as a hallmark of friction. Upon an increase of packing fraction, the flow curves show hysteretic behaviour, the emergence of a yield stress and the divergence of the shear viscosity - each at a different packing fraction. All the reported behaviour is reproduced with a simple model for a non-equilibrium first order phase transition. An inherent feature of dense frictional granular rheology is that the transition from flowing to jammed states is reentrant with transient jam-and-flow states in between which are, within the models' framework, metastable flow states.