title: Rheological properties vs. local dynamics in model disordered materials at low temperature.
abstract: We study the rheological response at low temperature of a sheared model disordered material as a function of the bond rigidity. We find that the flow curves follow a Herschel-Bulkley law, whatever is the bond rigidity, with an exponent close to 0.5. Interestingly, the apparent viscosity can be related to a single relevant time scale t rel, suggesting a strong connection between the local dynamics and the global mechanical behaviour. We propose a model based on the competition between the nucleation and the avalanche-like propagation of spatial strain heterogeneities. This model can explain the Herschel-Bulkley exponent on the basis of the size dependence of the heterogeneities on the shear rate.
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, F-69622, Villeurbanne Cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Fusco
authors.forename: T
authors.initials: T
authors.lastname: Albaret
authors.forename: A
authors.initials: A
authors.lastname: Tanguy