Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

Tri-axial deformation characteristics of Si-based particulate assemblies: a comparative study using DEM and atomistic simulations

M. Amin and S.J. Antony*
Institute of Particle Science and Engineering, Department of Chemical Engineering, University of Leeds, LS2 9JT, UK

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ABSTRACT
In this paper, we investigate the macroscopic and micromechnical behavior of Si based particulate systems subjected to tri-axial compression loading using the Discrete Element Method (DEM). We considered four types of Si based three-dimensional particulate assemblies: Si, SiC, Si3N4 and SiO2. The evolution of macroscopic mean strength of the assemblies and microscopic sliding characteristics of the assemblies are presented here. For the case of Si assembly, we compare the mean strength predicted from the current DEM simulations with the results obtained from Molecular Dynamics (MD) simulations reported by Mylvaganam and Zha [1] and a good qualitative agreement is obtained between the DEM and MD simulations at small strains. However, at large strains, the mean strength predicted from MD simulations does not scale-up with the DEM results. This discrepancy could be due to that MD simulations are only valid for particle contacts, which are independent of one another. They do not consider the inherent 'discrete' nature of particulates and induced anisotropy at bulk scale. The behavior of particulate assemblies at macroscopic scale strongly depends on the inherent discrete nature of the particles, their single-particle properties and induced anisotropy during mechanical loading.

Keywords:  Tri-axial compression; Granular materials; Powder mechanics; DEM; MD simulations

* Corresponding author. Tel.: +44 (113) 343 2409; Fax: +44 (113) 343 2405; E-mail: S.J.Antony@leeds.ac.uk