The effect of particle shape on the angle of repose test based calibration of discrete element models

Abstract

Discrete element method (DEM) is a Lagrangian description based numerical technique used for modelling the mechanical behavior of granular materials. For using the DEM model, the micromechanical parameter values used in the governing equations must be determined beforehand. This is the so-called calibration problem. In most of the cases these micromechanical parameters cannot be directly measured, their values must be systematically changed until the modeled macro behavior of the granular assembly will be the same, as the real-life behavior. In this article we propose the simplest possible calibration method, the so-called angle of repose test for application in case of agricultural crop product related problems. We examine the effect of particle shape on the value of angle of repose, ad give statistically acceptable empirical function to describe this dependence mathematically.

Agricultural Applications of the Discrete Element Method

“…Many studies regarding agricultural granular materials have used DEM modeling to validate the interaction of contacted particles and reproduce the dynamic behavior of agricultural particles based on the calibrated micromechanical parameters. The micromechanical parameters are almost difficult to measure directly, and their values need to be systematically modified according to the modeled macro behavior until the particle assembly is the same as the real behavior of the particle [3], [4], this is so-called calibration. The calibration is the most time-and resource-consuming part of the DEM modeling, and it would be a really good thing from application point of view to have an available database of pre-calibrated data for the different agricultural crop particles DEM simulations.…”

“…The relative error (RE) of the bulk angle of repose was 0.39% [13] using the particle scaled-up method in the DEM parameters calibration for rice grains. [3] used a two-spherical clump as the simulated shape of corn granules and calibrated the angle of repose of corn particles with the help of a cylinder shown in Fig. 6.…”