NUMERICAL-SIMULATION OF UNIAXIAL COMPRESSION OF A GRANULAR MATERIAL WITH WALL FRICTION

Computations of uniaxial compression of a granular material in a two-d imensional box (with the top plate moving downward) are presented, inc luding the effects of wall friction. The granular flow equations are s olved as a system of conservation laws plus a set of constitutive rela tions, using a conservative finite difference method. A high quality n umerical scheme for propagating the moving top plate is introduced. Co mpared to the overall uniform compression of the granular material, th e effects of friction lead to a greater compression of the material ne ar the top corners and to a lesser compression near the bottom corners of the 2D box. Two flow cells develop in the velocity field of the gr anular material. The dependence of the flow on a set of dimensionless parameters is discussed. The evolution of a initially inhomogeneous de nsity distribution is also simulated and analyzed.