Industrial & Engineering Chemistry Research, Vol.49, No.11, 5153-5165, 2010
Unsteady Shear of Dense Assemblies of Cohesive Granular Materials under Constant Volume Conditions
The response characteristics of dense assemblies of cohesive granular materials to unsteady simple shear in the quasi-static regime are investigated through discrete element method (DEM) simulations of monodisperse spherical and frictional particles in periodic domains at constant volume. The dynamics of the volume-averaged normal and shear stresses in materials, undergoing stop-and-go shearing and oscillatory shear, are studied in detail Furthermore, the evolution of microstructure anisotropy has been quantified through a fabric tensor The stresses and the microstructure anisotropy depend on the strain extent but not on the shear rate. They both undergo a transition following reversal of shear direction, which requires a shear strain of order unity to fully adapt