Image-based numerical study of three-dimensional meso-structure effects on damage and failure of heterogeneous coal-rock under dynamic impact loads--颗粒学报PARTICUOLOGY

Zheng, K., Qiu, B., Wang, Z., Li, X., Li, J., & Gao, K. (2020). Image-based numerical study of three-dimensional meso-structure effects on damage and failure of heterogeneous coal-rock under dynamic impact loads. Particuology, 51, 132-141. https://doi.org/10.1016/j.partic.2019.09.008

Image-based numerical study of three-dimensional meso-structure effects on damage and failure of heterogeneous coal-rock under dynamic impact loads

Kehong Zheng ^a, Bingjing Qiu ^a, Zhenyu Wang ^a *, Xuefeng Li ^b, Jianping Li ^c, Kuidong Gao ^d

a College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
b School of Energy and Mechanical Engineering, Nanjing Normal University, Nanjing 210000, China
c College of Mechanical and Electrical Engineering, China University of Mining and Technology, Xuzhou 221116, China
d College of Mechanical & Electrical Engineering, Shandong University of Science & Technology, Qingdao 266000, China

10.1016/j.partic.2019.09.008

Volume 51, August 2020, Pages 132-141

Received 24 April 2019, Revised 30 June 2019, Accepted 23 September 2019, Available online 21 January 2020, Version of Record 11 April 2020.

E-mail: wzyu@zju.edu.cn

Highlights

• A numerical 3D approach is proposed to characterize the mechanical behavior of HCR.

• The effects of the 3D meso-structure of HCR on failure patterns are studied.

• The quantitative analysis results of the image-based 3D DE model are discussed.

Abstract

This paper proposes a numerical three-dimensional (3D) mesoscopic approach based on the discrete element method combined with X-ray computed tomography (XCT) images to characterize the dynamic impact behavior of heterogeneous coal-rock (HCR). The dynamic impact loading in three directions was modelled to investigate the effects of the 3D meso-structure on the failure patterns and fracture mechanism, with different impact velocities. The XCT image-based discrete element model of HCR was calibrated through appropriate standard uniaxial compression tests. Numerical simulations were carried out to investigate how the breakage behaviors are affected by different loading directions with different impact velocities. The loading direction, input energy, and spatial distribution of the mineral phase had a remarkable influence on the failure patterns and load-carrying capacities. The shape of the gangue phase and the approximate location of the gangue interfaces are key parameters to consider when investigating the failure patterns and fracture mechanism of heterogeneous rock materials. The damage and fracture tended to propagate from the surfaces to the HCR interior. The gangue phase area contacting the loading wall, growth direction of the strong gangue interfaces, and loading directions greatly influenced the failure patterns of the heterogeneous rock materials.

Graphical abstract

Keywords

Heterogeneous coal-rock; Impact loads; X-ray computed tomography (XCT); 3D image-based discrete element modelling; Failure pattern

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