Modeling slow deformation of polygonal particles using DEM
PARTICUOLOGY, 6 (6):
506-514 (2008)DOI: 10.1016/j.partic.2008.07.009
Abstract
We introduce two improvements in the numerical scheme to simulate
collision and slow shearing of irregular particles. First, we propose an
alternative approach based on simple relations to compute the frictional
contact forces. The approach improves efficiency and accuracy of the
Discrete Element Method (DEM) when modeling the dynamics of the granular
packing. We determine the proper upper limit for the integration step in
the standard numerical scheme using a wide range of material parameters.
To this end, we study the kinetic energy decay in a stress controlled
test between two particles. Second, we show that the usual way of
defining the contact plane between two polygonal particles is, in
general, not unique which leads to discontinuities in the direction of
the contact plane while particles move. To solve this drawback, we
introduce an accurate definition for the contact plane based on the
shape of the overlap area between touching particles, which evolves
continuously in time. (c) 2008 Chinese Society of Particuology and
Institute of Process Engineering, Chinese Academy of Sciences. Published
by Elsevier B.V. All rights reserved.