Shear thickening and jamming of dense suspensions: the importance of rolling friction

The mechanism of shear thickening in dense suspensions has been linked to a stress-controlled transition from a lubricated ``frictionless'' to an unlubricated ``frictional'' rheology. Recent particle simulations that constrain the sliding motion between particles have been successful to reproduce both the discontinuous shear thickening (DST) and shear jamming (SJ) observed experimentally but cannot account for the surprisingly low SJ volume fraction (often below 50%) measured in real-life suspensions in which particles are rough. However, an additional way to build up and maintain stress-carrying paths across a suspension, particularly relevant to rough particles, is by constraining particle rolling. We show via simulations that using rolling friction together with sliding friction can significantly decrease the volume fraction required for the onset of DST and SJ leading to enhanced shear thickening. Moreover, rolling friction drastically affects the structure of the underlying network of frictional particle-particle contacts, while from a dynamical perspective it leads to an increase in the velocity correlation length, in part responsible for the increased dissipation.