Constitutive relations for the shear band evolution in granular matter under large strain

摘要: A so-called “split-bottom ring shear cell” leads to wide bands under slow, quasi-static deformation. Unlike normal cylindrical Couette cells or rheometers, the bottom plate is split such that outer part of it can move with wall, while other (inner disk) immobile. From discrete element simulations (DEM), several continuum fields like density, velocity, deformation gradient and stress are computed evaluated goal formulate objective constitutive relations for powder flow behavior. a single simulation, by applying time- (local) space-averaging, non-linear yield surface obtained peculiar dependence. The anisotropy always smaller than macroscopic friction coefficient. However, lower bound increases strain rate, approaching maximum according stretched exponential specific rate consistent path about one particle diameter.