在线阅读

在线阅读

Partic. vol. 34 pp. 14-23 (October 2017)
doi: 10.1016/j.partic.2016.08.007

Implementation of rotational resistance models: A critical appraisal

Xin Huanga, b, *, Kevin J. Hanleyc, Catherine O’Sullivand, Chung-Yee Kwoke

Show more

xhuang@tongji.edu.cn

Highlights

    • The critical time step for rotational resistance models was derived. • Analytical solutions for model validation scenarios were derived. • Transition from rolling to sliding at contact points was identified. • The limitations of rotational resistance models were discussed.

Abstract

Contact models that simulate rotational resistance at particle contacts have been proposed as a means to capture the effect of shape in DEM simulations. This contribution critically explores some key issues related to the implementation of rotational resistance models; these include the need for physically meaningful model parameters, the impact of the model on the overall numerical stability/critical time increment for the DEM model, model validation, and the assessment of model performance relative to real physical materials. The discussion is centred around a rotational resistance model that captures the resistance provided by interlocking asperities on the particle surface. An expression for the maximum permissible integration time step to ensure numerical stability is derived for DEM simulations when rotational resistance is incorporated. Analytical solutions for some single-contact scenarios are derived for model validation. The ability of this type of model to provide additional fundamental insight into granular material behaviour is demonstrated using particle-scale analysis of triaxial compression simulations to examine the roles that contact rolling and sliding have on the stability of strong force chains.

Graphical abstract

Keywords

Granular media; Particle shape; Discrete element method; Rolling; Twisting; Rotational resistance