Microscopic mechanism for the shear-thickening of non-Brownian suspensions

摘要

We propose a simple model, supported by contact-dynamics simulations as wellas rheology and friction measurements, that links the transition fromcontinuous to discontinuous shear-thickening in dense granular pastes todistinct lubrication regimes in the particle contacts. We identify a localSommerfeld number that determines the transition from Newtonian toshear-thickening flows, and then show that the suspension's volume fraction andthe boundary lubrication friction coefficient control the nature of theshear-thickening transition, both in simulations and experiments.