基于纳米压痕的煤系泥岩细观力学及断裂性能试验研究

doi:10.11799/ce202302023

摘要/Abstract

摘要： 以口孜东煤矿煤系泥岩为对象，开展了纳米压痕试验，基于弹性接触理论以及能量原理，研究了泥岩岩样的细观力学性质及断裂力学特征，探讨了泥岩内部不同矿物成分之间的细观力学行为差异。研究结果表明：相同的最大压痕载荷条件下，泥岩表面压痕点深度变化不一，压痕点弹性模量约在2～114GPa范围内，而硬度在0～16GPa范围内变化，体现了泥岩的不均质性|基于弹性模量概率分布曲线，近似获得了泥岩三种主要的矿物成分，包括黏土类矿物(～ 7.83GPa)、绿泥石类矿物(～ 41.67GPa)以及石英矿物(～ 97.29GPa)|黏土类矿物、绿泥石类矿物及石英矿物的断裂韧度分别约为0.09、0.91和1.95MPa·m1/2，而黏土类矿物断裂韧度所占比例较高(～70.0%)，该矿物对泥岩宏观断裂力学性质起决定性作用。

关键词: 煤系泥岩, 纳米压痕, 弹性模量, 能量法, 断裂韧度

Abstract: Taking the mudstone obtained from Kouzidong coal mine, Fuyang, Anhui, as the research object, nanoindentation test was carried out on this mudstone. Based on the elastic theory and energy principle, the meso-mechanical properties and fracture characteristic were investigated. Furthermore, difference in meso-mechanical properties of main composition of mudstone was analyzed. Results showed that under the same maximum load, the indentation depth on the mudstone surface varied different. The elastic modulus was in the range of 2-114 GPa, and the hardness ranged from 0 GPa to 16 GPa, reflecting the heterogeneity of the mudstone. Based on the probability density distribution of modulus, three different main phases were identified, including clay minerals (~ 7.83 GPa, including kaolinite and illite), chlorite (~ 41.67 GPa) and quartz (~ 97.29 GPa). Morever, the fracture toughness of clay minerals, chlorite and quartz was 0.09, 0.91 and 1.95 MPa·m1/2, respectively. The fracture toughness of clay minerals accounted for the largest proportion (~ 70.0 %), and the clay minerals played a significant effect in macro-fracture properties. By the obtained mesoscopic mechanical properties and fracture toughness of different phases of mudstone, it was useful to understand the macroscopic failure behaviour of mudstone.

中图分类号:

TD315

顾士坦, 逯英棋, 李文帅, 等. 基于纳米压痕的煤系泥岩细观力学及断裂性能试验研究[J]. 煤炭工程, 2023, 55(2): 128-133.

参考文献

[1] Lu Yinlong, Wang Lianguo, Sun Xiaokang, et al. Experimental study of the influence of water and temperature on the mechanical behavior of mudstone and sandstone[J]. Bulletin of Engineering Geology and the Environment, 2017, 76(2): 645-660.
[2] Kang Yongshui, Liu Quansheng, Gong Guangqing, et al. Application of a combined support system to the weak floor reinforcement in deep underground coal mine[J]. International Journal of Rock Mechanics and Mining Sciences, 2014, 71: 143-150.
[3] Li Ming, Mao Xianbiao, Cao Lili, et al. Effects of thermal treatment on the dynamic mechanical properties of coal measures sandstone[J]. Rock Mechanics and Rock Engineering, 2016, 49(9): 3525-3539.
[4] 沈书豪, 吴基文, 翟晓荣, 等. 深部地应力场下煤系岩石力学性质变化规律[J]. 采矿与安全工程学报, 2017, 34(6): 1200-1206.
SHEN Shuhao, WU Jiwen, ZHAI Xiaorong, et al. Variation of mechanical properties of coal and rocks in the deep mine in-situ stress fieid[J]. Journal of Mining & Safety Engineering, 2017, 34(6): 1200-1206.
[5] 李化敏, 李回贵, 宋桂军, 等. 神东矿区煤系地层岩石物理力学性质[J]. 煤炭学报, 2016, 41(11): 2661-2671.
LI Huamin, LI Huigui, SONG Guijun, et al. Physical and mechanical properties of the coal-bearing strata rock in Shendong coal field[J]. Journal of China Coal Society, 2016, 41(11): 2661-2671.
[6] Lu Yinlong, Li Wenshuai, Wang Lianguo, et al. In-situ microscale visualization experiments on microcracking and microdeformation behaviour around a pre-crack tip in a three-point bending sandstone[J]. International Journal of Rock Mechanics and Mining Sciences, 2019, 114: 175-185.
[7] Oliver W-C, Pharr G-M. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments[J]. Journal of Materials Research, 1992, 7(6): 1564-1583.
[8] Constantinides G, Chandran KSR, Ulm FJ, Vliet KJV. Grid indentation analysis of composite microstructure and mechanics[J]. Materials Science and Engineering A, 2006, 430(1-2): 189-202.
[9] Zhang Yihuai, Lebedev M, Al-Yaseri A, et al. Characterization of nanoscale rockmechanical properties and microstructures of a Chinese sub-bituminous coal[J]. Journal of Natural Gas Science and Engineering, 2018, 52: 106-116.
[10] 陈立超, 王生维, 张典坤. 煤岩脆性特征压痕法评价及储层改造意义[J]. 煤炭学报, 2020, 46(S02): 955-964.
CHEN Lichao, WANG Shengwei, ZHANG Diankun. Brittleness evaluation of coal rock based on indentation method and the significance of coal reservoir stimulation[J]. Journal of China Coal Society, 2020, 46(S02): 955-964.
[11] Ante M, Lingareddy M, Aminzadeh F, Jha B. Nano- and Micro-Scale Deformation Behavior of Sandstone and Shale[C].52nd US Rock Mechanics/Geomechanics Symposium,2018.
[12] Lu Yunhu, Li Yucheng, Wu Yongkang, et al. Characterization of shale softening by large volume-based nanoindentation[J]. Rock Mechanics and Rock Engineering, 2019, 53(3): 1393-1409.
[13] Barbhuiya S, Caracciolo B. Characterisation of asphalt concrete using nanoindentation[J]. Materials, 2017, 10(7): 823.
[14] Lee H, Vimonsatit V, Chindaprasirt P. Mechanical and micromechanical properties of alkali activated fly-ash cement based on nano-indentation[J]. Construction and Building Materials, 2016, 107: 95-102.
[15] Zhang Sam, Zhang Xiaomin. Toughness evaluation of hard coatings and thin films[J]. Thin Solid Films, 2012, 520(7): 2375-2389.
[16] Broz ME, Cook RF, Whitney DL. Microhardness, toughness, and modulus of Mohs scale minerals[J]. American Mineralogist, 2006, 91(1): 135-142.
[17] Chen J, Bull S. Indentation fracture and toughness assessment for thin optical coatings on glass[J]. Journal of Physics D: Applied Physics, 2007, 40(18): 5401.
[18] Liu Kouqi, Ostadhassan M, Bubach B. Applications of nano-indentation methods to estimate nanoscale mechanical properties of shale reservoir rocks[J]. Journal of Natural Gas Science and Engineering, 2016, 35: 1310-1319.
[19] Xu Shiliang, Liu Jiahan. Micro Indentation Fracture Toughness Assessed by Energy-Based Method: The Method Improvement and Affecting Factors[J]. Social science electronic publishing, 2019.
[20] 冯莹, 彭宇, 徐世烺, 等. 钢纤维砂浆纳米压痕微观断裂性能表征[J].硅酸盐学报,2018: 1593-1602.
FENG Ying, PENG Yu, XU Shilang, et al. Micro Fracture Characterization of Steel Fiber Reinforced Mortar by Nanoindentation[J]. Journal of the Chinese Ceramic Society, 2018: 1593-1602.
[21] 江俊达, 沈吉云, 侯东伟. 基于纳米压痕的水化硅酸钙断裂韧度测试与计算方法[J]. 硅酸盐学报, 2018, 46(8): 1067-1073.
JIANG Junda, SHEN Jijun, HOU Dongwei, Determination of Fracture Toughness of Hydrated Calcium Silicate by Nanoindentation[J]. Journal of the Chinese Ceramic Society, 2018, 46(8): 1067-1073.
[22] Liu Kouqi, Ostadhassan M, Bubach B, et al. Statistical grid nanoindentation analysis to estimate macro-mechanical properties of the Bakken Shale[J]. Journal of Natural Gas Science and Engineering, 2018, 53: 181-190.
[23] Oliver WC, Pharr GM. An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments[J]. Journal of Materials Research, 1992, 7(6): 1564-1583.
[24] Zhu Xingyi, Yuan Ying, Li Lihan, et al. Identification of interfacial transition zone in asphalt concrete based on nano-scale metrology techniques[J]. Materials and Design, 2017, 129: 91-102.
[25] 徐世烺. 混凝土断裂力学[M]. 北京: 科学出版社, 2011.
XU Shilang. Fracture Mechanics of concrete[M]. Beijing: Science Press, 2011.
[26] Fischer-Cripps AC. Nanoindentation[M]. 2004.
[27] Zhu Wenzhong, Hughes JJ, Bicanic N, et al. Nanoindentation mapping of mechanical properties of cement paste and natural rocks[J]. Materials Characterization, 2007, 58: 1189-1198.
[28] Xiao Jianzhuang, Li Wengui, Sun Zhihui, et al. Properties of interfacial transition zones in recycled aggregate concrete tested by nanoindentation[J]. Cement and Concrete Composites, 2013, 37(3): 276-292.
[29] Něme?ek J. Creep effects in nanoindentation of hydrated phases of cement pastes[J]. Materials Characterization, 2009, 60(9): 1028-1034.
[30] Zhang Fan, Guo Hanqun, Hu Dawei, et al. Characterization of the mechanical properties of a claystone by nano-indentation and homogenization[J]. Acta Geotechnica, 2018, 13(6): 1395-1404.