DEM parameter calibration of cohesive bulk materials using a simple angle of repose test--颗粒学报PARTICUOLOGY

Roessler, T., & Katterfeld, A. (2019). DEM parameter calibration of cohesive bulk materials using a simple angle of repose test. Particuology, 45, 105-115. https://doi.org/10.1016/j.partic.2018.08.005

DEM parameter calibration of cohesive bulk materials using a simple angle of repose test

Thomas Roessler ^*, André Katterfeld

Chair of Material Handling, Institute of Logistics and Material Handling Systems, University of Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany

10.1016/j.partic.2018.08.005

Volume 45, August 2019, Pages 105-115

Received 11 January 2018, Revised 28 June 2018, Accepted 16 August 2018, Available online 25 January 2019, Version of Record 10 June 2019.

E-mail: throessl@ovgu.de

Highlights

• The lifting cylinder test is introduced for cohesive-material DEM calibration.

• There are four characteristic phases of flow behaviour when lifting the cylinder.

• Characteristic phases are independent of the cylinder size and lifting velocity.

• Convex bending and collapse of a material column are introduced as new references.

• DEM parameters are calibrated by measuring convex bending via an analysis algorithm.

Abstract

The numerical effort of discrete element method (DEM) simulations results in a general idealisation of DEM models that makes the calibration crucial to obtaining realistic simulation results. The angle of repose test has become a standard test for the calibration of DEM parameters of cohesionless bulk materials and is extensively discussed in the literature. One of the most used test methods is the pull-up test of a hollow cylinder filled with bulk material. This paper presents how this basic pull-up test can also be used for the calibration of DEM parameters of cohesive materials by changing the analysis criteria. In contrast to analysing the static angle of repose, the focus lies on the macroscopic flow behaviour during the lifting of the cylinder. Reproducible phases of flow are identified in experiments: the build-up of a stable bulk material column, the convex bending of the column, and the beginning of collapse of the column. Furthermore, the phases are independent of the size and lifting velocity. The convex bending of the bulk-material column combined with the moment of first collapse are introduced as new measurable calibration criteria. These experimental results of wet sand are used for the calibration of related DEM parameters using a simplified JKR cohesion model. The DEM calibration including an analysis algorithm that fits the experimental flow behaviour and the final selection of the relevant parameters (i.e., sliding friction coefficient, rolling friction coefficient, and cohesion energy density) is presented in detail.

Graphical abstract

Keywords

Discrete element method; Angle of repose; Cohesive bulk material; Calibration

文章导读