Input Parameters of Discrete Element Methods
Publication: Journal of Engineering Mechanics
Volume 132, Issue 7
Abstract
This paper presents a sensitivity analysis of the input parameters of a program based on the discrete element method (DEM). Triaxial compression simulations were conducted on an assembly of ellipsoids with two particle shapes. We examine four input parameters including shear modulus of particles, density of particles, time step, and damping. Generally, these parameters are chosen by calibrating the result with certain known behavior of granular materials. In dynamic simulations, these input parameters are bounded by their physical attributions that should not be altered. However, in static simulations, they do not have the same physical implication. Validity of results may be questionable when input parameters are used without justification. A sensitivity analysis of the input parameters should shed light on this issue. In this paper, we will study the effect of the input values within the range of times the benchmark value. The benchmark values are commonly used by the writer. The results are presented against the benchmark simulation. The unbalanced forces in the simulations are kept below a prescribed value to enforce equilibrium. The result shows that the effect of all input parameters used in this paper is negligible as long as the small unbalanced forces in the system can be achieved. The runtimes are different. However, there are two simulations (one with low damping and the other with a large time step size) that cannot maintain the required small unbalanced force. In other words, equilibrium cannot be achieved for these simulations.
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Information & Authors
Information
Published In
Journal of Engineering Mechanics
Volume 132 • Issue 7 • July 2006
Pages: 723 - 729
Copyright
© 2006 ASCE.
History
Received: Dec 7, 2004
Accepted: Oct 14, 2005
Published online: Jul 1, 2006
Published in print: Jul 2006
Notes
Note. Associate Editor: Ching S. Chang
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