On the breakage function for constructing the fragment replacement modes--颗粒学报PARTICUOLOGY

Zhou, W., Xu, K., Ma, G., & Chang, X. (2019). On the breakage function for constructing the fragment replacement modes. Particuology, 44, 207-217. https://doi.org/10.1016/j.partic.2018.08.006

On the breakage function for constructing the fragment replacement modes

Wei Zhou ^{a c}, Kun Xu ^{a b c *}, Gang Ma ^{a c}, Xiaolin Chang ^{a c}

a State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
b Changjiang Institute of Survey, Planning, Design and Research, Wuhan 430010, China
c Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering, Ministry of Education, Wuhan University, Wuhan 430072, China

10.1016/j.partic.2018.08.006

Volume 44, June 2019, Pages 207-217

Received 6 July 2017, Revised 17 July 2018, Accepted 15 August 2018, Available online 26 January 2019, Version of Record 30 April 2019.

E-mail: xukun_2013@whu.edu.cn

Highlights

• Single particle compression tests were successfully simulated in DEM.

• Single particle fragmentation is a gradually occurring process.

• A two-stage distribution model for breakage function was proposed.

• The proposed model performs well compared with experimental and numerical results.

Abstract

The fragment replacement method (FRM), a particle breakage simulation method, is often used in discrete element simulations to investigate the particle breakage effect on the mechanical behavior of granular materials. The fragment size distribution of the fragment replacement mode of FRM, which is generally generated based on the fragmentation characteristics of single particles after uniaxial compression, affects the breakage process and the mechanical behavior of the particle assembly. However, existing fragment replacement modes are seldom generated based on experimental data analysis. To capture the fragmentation process and investigate the breakage function for the construction of the fragment replacement mode, 60 numerical single particle compression tests were implemented by DEM. The bonded-particle model was applied to generate the crushable rock particles. The numerical simulations were qualitatively validated by experimental results, and the fragment size of broken single particles was analyzed. The fractal dimension was used to describe the fragmentation degree of single particles after compression. The fragmentation degree was random, and the fractal dimensions of the 60 tests at the same loading displacement fit the Weibull distribution well. The characteristic fractal dimension increased with increasing loading displacement, indicating that the fragmentation of single particles is a gradual process. According to the overall breakage function of the 60 tests at the first bulk breakage, a two-stage distribution model with 4 parameters was proposed and validated by the numerical and experimental results. The various fracture patterns of a single particle at the first bulk breakage under compression tests were well captured by the two-stage distribution model. Finally, an initial application strategy using the two-stage distribution model to construct fragment replacement modes was discussed and presented.

Graphical abstract

Keywords

Particle breakage; Single particle compression test; DEM; Fragment replacement mode; Breakage function

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