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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 61: Focus: Disordered Systems, Glasses under Shear I (joint session CPP, DY)
CPP 61.8: Talk
Thursday, March 19, 2015, 12:00–12:15, C 243
Shear bands at the Jamming Transition: The role of Weak Attractive Interactions — •Ehsan Irani1, Pinaki Chaudhuri2, and Claus Heussinger1 — 1Institut für Theoretische Physik, Georg-August-Universität Göttingen, Göttingen, Germany — 2Institute of Mathematical Sciences, Tamil Nadu, India
We study the rheology of a particulate sytem close to Jamming in the presence of weakly attractive interactions. Lees-Edwards boundary conditions are used to simulate a shear-controlled flow. In addition to Bagnold scaling at large shear rates, the attraction results in a finite yield stress in the limit of small shear rates. In the yield regime a fragile solid is formed and the rheology can be explained by a scaling argument that exploits the vicinity to the isostatic state. In the transition region the shear stress develops a minimum, which (in large enough systems) leads to the formation of persistent shear bands. These features are rationalized by a scenario that involves the competition between attraction-induced structure formation and its break-down because of shearing. Properties of shear bands are studied in order to reveal the physical mechanisms that underly the non-monotonic flow curve and the flow heterogenities in the transition region. This work may help to elucidate the origin of shear bands in different materials with finite and short-ranged attractive forces.