基于纳米压痕的构造煤与原生煤结构面力学特性  

Mechanical properties instructural planes of tectonic coal and primary coal through nano-indentation

作　　者：郭敬杰 李伟[1,2,3] 韩祥凯[1,2,3] 花春雨 邓东 GUO Jingjie;LI Wei;HAN iangkai;HUA Chunyu;DENG Dong(State Key Laboratory of Coal Mine Disaster Prerention and Control,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;National Engineering Research Center for Coal Gas Control,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学煤矿灾害防控全国重点实验室,江苏徐州221116 [2]中国矿业大学煤矿瓦斯治理国家工程研究中心,江苏徐州221116 [3]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《中国矿业大学学报》2024年第3期509-523,共15页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(52374243,51874295);中央高校基本科研业务费专项资金资助项目(2023XSCX036);江苏省研究生科研与实践创新计划资助(KYCX23_2846);中国矿业大学研究生创新计划项目资助(2023WLKXJ137)。

摘　　要：煤与瓦斯突出等矿井动力灾害严重威胁矿井安全高效生产,不同煤体的微观强度、变形和流变特性的研究对矿井高效生产和灾害防治具有重要意义.本文采用纳米压痕技术对典型的构造煤和原生煤试样的结构面进行了测试,研究了构造煤与原生煤的微观强度、变形、加卸载速率敏感性和蠕变特性.结果表明:相同载荷条件下构造煤变形能力比原生煤更强,弹性恢复能力更弱,构造煤的变形耗散能约为原生煤的2倍,二者结构面存在部分相似的特性.随加卸载速率降低弹性能占比升高,耗散能、弹性模量、刚度下降;载荷加卸载速率小于100μN/s时,强度特性存在较大的波动,载荷加卸载速率大于100μN/s时,强度特性随着速率变化波动变小,当载荷加载速率远大于卸载速率时会出现初始卸载时刻出现应力滞后现象.构造煤在不同载荷条件下蠕变变形能力均大于原生煤,伯格斯模型可以描述煤体纳米压痕条件下蠕变趋势,但不能很好地描述弹性恢复现象,分数阶麦克斯韦模型可以精确描述纳米压痕条件下煤体的蠕变过程.Coal and gas outbursts, alongside other dynamic hazards within mines, are known to pose a severe threat to both mine safety and the efficiency of production. Consequently, the research into the micro-scale strength, deformation, and rheological properties of various coal types takes on substantial importance in the context of enhancing mine production efficiency and averting potential disasters. In this study, nano-indentation technology was employed to conduct tests on the structural planes of typical tectonic coal and primary coal specimens, with a focus on investigating the micro-scale strength, deformation, rate sensitivity, and creep characteristics of these coal varieties. The results show that, under equivalent loading conditions, tectonic coal exhibits greater deformability compared to primary coal, accompanied by weaker elastic recovery. The deformation dissipation energy in tectonic coal is approximately double that observed in primary coal, and certain structural similarities between the two are evident. As the loading and unloading rates are reduced, there is an associated increase in the proportion of elastic energy, while dissipation energy, elastic modulus, and stiffness decrease. It is noteworthy that when the loading and unloading rates fall below 100 μN/s, significant fluctuations are observed in the strength characteristics. Conversely, for loading and unloading rates exceeding 100 μN/s, strength characteristics display reduced fluctuations with varying rates. Moreover, when the loading rate significantly exceeds the unloading rate, stress hysteresis is observed during the initial unloading moments. Furthermore, greater creep deformation capacity is exhibited by tectonic coal in comparison to primary coal under varying loading conditions. The creep trends of coal under nanoindentation conditions are described by the Burgers model, although it is unable to accurately capture the phenomenon of elastic recovery. In contrast, the creep process of coal under nano-indentation conditions is precisel

关 键 词：纳米压痕 构造煤 结构面 率相关 蠕变 煤与瓦斯突出 

分 类 号：TD313[矿业工程—矿井建设]