Quantified evaluation of particle shape effects from micro-to-macro scales for non-convex grains--颗粒学报PARTICUOLOGY

Yang, Y., Wang, J. F., & Cheng, Y. M. (2016). Quantified evaluation of particle shape effects from micro-to-macro scales for non-convex grains. Particuology, 25, 23-35. https://doi.org/10.1016/j.partic.2015.01.008

Quantified evaluation of particle shape effects from micro-to-macro scales for non-convex grains

Y. Yang ^a, J.F. Wang ^b, Y.M. Cheng ^a *

a Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hong Kong, China
b Department of Civil and Architectural Engineering, City University of Hong Kong, Hong Kong, China

10.1016/j.partic.2015.01.008

Volume 25, April 2016, Pages 23-35

Received 28 July 2014, Revised 20 November 2014, Accepted 30 January 2015, Available online 22 June 2015, Version of Record 18 February 2016.

E-mail: ceymchen@polyu.edu.hk

Highlights

• SF is a better shape descriptor in evaluating granular mechanical behaviour.

• Strength indexes and anisotropic coefficients increased linearly with SF at steady state.

• Average normal contact forces and contact vectors could influence stress–force–fabric accuracy.

• Frictional mobilization and contact force chain could be used to explain macro physical property.

Abstract

Particle shape plays an important role in both the micro and macro scales responses of a granular assembly. This paper presents a systematic way to interpret the shape effects of granular material during quasi-static shearing. A more suitable shape descriptor is suggested for the quantitative analysis of the macroscale strength indexes and contact parameters for non-convex grains, with special consideration given to the peak state and critical state. Through a series of numerical simulations and related post-processing analysis, particle shape is found to directly influence the strain localisation patterns, microscale fabric distributions, microscale mobilisation indexes, and probability distribution of the normalised contact normal force. Additionally, the accuracy of the stress–force–fabric relationship can be influenced by the average normal force and the distribution of contact vectors. Moreover, particle shape plays a more important role than do the confining pressures in determining the friction angle. Strong force chains and the dilation effect are also found to be strongly influenced by the high confining pressure.

Graphical abstract

Keywords

Quantitative analysis; Shape factor; Statistical analysis; Micro–macro indexes

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