Experimental and numerical study of failure behavior and mechanism of coal under dynamic compressive loads
Experimental and numerical study of failure behavior and mechanism of coal under dynamic compressive loads
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DOI：
10.1016/j.ijmst.2020.06.004
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发表时间：
2020-09-01
影响因子：
11.8
通讯作者：
Zhang, Xiangyang
中科院分区：
文献类型：
--
作者：
Feng, Junjun;Wang, Enyuan;Zhang, Xiangyang
全面认识煤的破坏行为和破坏机理是处理采动空间动力学问题的前提。本文对煤岩在单轴动态压缩载荷作用下的破坏行为和破坏机理进行了实验研究和数值模拟。实验采用分离式霍普金森压杆（SHPB）系统。结果表明，在较低的加载速率下，煤体的典型破坏形式为侧向和轴向破坏，而在较高的加载速率下，煤体的破坏形式为完全破碎。进一步的横向和轴向断口分析表明，煤在动态压缩载荷下的破坏是由拉伸脆性断裂引起的。此外，数值模拟再现了煤在动荷载作用下的典型破坏模式。结果表明，轴向断裂是由入射的压应力波直接引起的，侧向断裂是由煤样与透射杆界面反射的拉应力波引起的。进一步应用于解释煤矿井下的动力学问题，表明煤体的横向和轴向断裂构成了采动空间中顶板冒落和爆破作用下煤体中的平行裂纹。(C)2020由Elsevier B.V.代表中国矿业大学出版。
A comprehensive understanding of the failure behavior and mechanism of coal is a prerequisite for dealing with dynamic problems in mining space. In this study, the failure behavior and mechanism of coal under uniaxial dynamic compressive loads were experimentally and numerically investigated. The experiments were conducted using a split Hopkinson pressure bar (SHPB) system. The results indicated that the typical failure of coal is lateral and axial at lower loading rates and totally smashed at higher loading rates. The further fractography analysis of lateral and axial fracture fragments indicated that the coal failure under dynamic compressive load is caused by tensile brittle fracture. In addition, the typical failure modes of coal under dynamic load were numerically reproduced. The numerical results indicated that the axial fracture is caused directly by the incident compressive stress wave and the lateral fracture is caused by the tensile stress wave reflected from the interface between coal specimen and transmitted bar. Potential application was further conducted to interpret dynamic problems in underground coal mine and it manifested that the lateral and axial fractures of coal constitute the parallel cracks in the coal mass under roof fall and blasting in mining space. (C) 2020 Published by Elsevier B.V. on behalf of China University of Mining & Technology.