DEM investigation of angle of repose for super-ellipsoidal particles--颗粒学报PARTICUOLOGY

Chen, H., Zhao, S., & Zhou, X. (2020). DEM investigation of angle of repose for super-ellipsoidal particles. Particuology, 50, 53-66. https://doi.org/10.1016/j.partic.2019.05.005

DEM investigation of angle of repose for super-ellipsoidal particles

Hao Chen, Shiwei Zhao ^*, Xiaowen Zhou

State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou 510641, China

10.1016/j.partic.2019.05.005

Volume 50, June 2020, Pages 53-66

Received 8 November 2018, Revised 20 April 2019, Accepted 20 May 2019, Available online 17 July 2019, Version of Record 7 April 2020.

E-mail: swzhao@scut.edu.cn

Highlights

• DEM analysis of particle shape on angle of repose for super-ellipsoidal particles.

• Approximate M-shape dependence of aspect ratio on angle of repose for varying blockiness.

• Microscopic viewpoint of influence of mechanical properties on angle of repose.

Abstract

We explore the effect of particle shape on the angle of repose (AoR) in granular packing using a three-dimensional discrete element method. Non-spherical particles were modeled using super-ellipsoids characterized by aspect ratio and blockiness. The relationship between AoR and particle shape was examined, followed by a series of analyses on the origin of AoR from a microscopic perspective. Results show that, with blockiness deviating from unity, AoR has an approximate "M" shape that exhibits a strong to weak trend with aspect ratio, matching results of previous reports. Another finding suggests a parabolic relationship between normalized AoR and normalized coordination number. AoR increases with anisotropy related more with the anisotropy of particle orientation than with the anisotropy of contact normal. Particle shape is more likely to affect AoR by affecting the tangential force than the normal contact force. An analysis based on traction indicates that dips in stress associated with the tangential force (compared with the normal force) and non-spherical particles (compared with spheres) are more significant. For various particle shapes, AoR is positively correlated with friction mobilization but is negatively correlated with friction mobilization for various coefficient of friction.

Graphical abstract

Keywords

Discrete element; Angle of repose; Non-spherical particles; Granular fabric; Packing

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