Continuous and discontinuous shear thickening in granular suspensions

Abdoulaye Fall (1, 2) , Anael Lemaitre (3) , François Bertrand (4) , Daniel Bonn (2, 5) , Guillaume Ovarlez (3)

1 navier umr 8205 - Laboratoire Navier
2 VAN DER WAALS-ZEEMAN INSTITUTE - University of Amsterdam Van der Waals-Zeeman Institute
3 Rhéophysique
4 Physique des milieux poreux
5 LPS - Laboratoire de Physique Statistique de l'ENS

We study the emergence of shear thickening in dense suspensions of non-Brownian particles. We combine local velocity and concentration measurements using Magnetic Resonance Imaging with global rheometric experiments. We evidence a continuous transition at very low shear rate from a viscous to a shear thickening, granular, rheology characterized by shear stresses proportional to the shear rate squared. We show that an unexpectedly fast migration of grains occurs towards low shear zones as a result of the granular rheology. Combining local and global measurements allow to show that the interplay between flow and migration is responsible for the macroscopic observation of discontinuous shear thickening, but that locally the shear thickening is continuous.

Mots clés: Shear thickening; suspension; granular material; migration

Domaines: Matière Molle [cond-mat.soft]

Abdoulaye Fall, Anael Lemaitre, François Bertrand, Daniel Bonn, Guillaume Ovarlez. Continuous and discontinuous shear thickening in granular suspensions. 2010. ⟨hal-00490742v1⟩