Revealing the frictional transition in shear thickening suspensions

C Clavaud (1) , A Bérut (1) , B Metzger (1) , Yoel Forterre (1)

1 IUSTI - Institut universitaire des systèmes thermiques industriels

Shear thickening in dense particulate suspensions was recently proposed to be driven by the activation of friction above an onset stress arising from short range repulsive forces between particles. Testing this scenario represents a major challenge since classical rheologi-cal approaches do not provide access to the frictional properties of suspensions. Here we adopt a new strategy inspired by pressure-imposed configurations in granular flows that specifically gives access to this information. By investigating the quasistatic avalanche angle, compaction, and dilatancy effects in different nonbuoyant sus-pensions flowing under gravity, we demonstrate that particles in shear-thickening suspensions are frictionless under low confining pressure. Moreover, we show that tuning the range of the repulsive force below the particle roughness suppresses the frictionless state and also the shear-thickening behavior of the suspension. These results, which link microscopic contact physics to the suspension macroscopic rheology, provide direct evidences that the recent fric-tional transition scenario applies in real suspensions.

Mots clés: friction; soft matter; shear thickening; dense suspensions

Domaines: Matière Molle [cond-mat.soft]

C Clavaud, A Bérut, B Metzger, Yoel Forterre. Revealing the frictional transition in shear thickening suspensions. Proceedings of the National Academy of Sciences of the United States of America, 2017, 114 (20), pp.5147-5152. ⟨10.1073/pnas.1703926114⟩. ⟨hal-01492671⟩