Energy mechanism analysis on elastoplastic damage of coal under cyclic loading

doi:10.16265/j.cnki.issn1003-3033.2020.05.014

Abstract

Abstract: In order to explore damage deformation and energy evolution mechanism of coal under periodic disturbance of stress, cyclic loading tests with different time lengths of stabilization were carried out by using servo-controlled triaxial seepage device for thermo-fluid-solid coupling of coal containing methane. Then, based on analyses of energy parameters, a calculation formula of damage variables of coal under cyclic loading was derived, and evolution behaviors of its elastoplastic damage were analyzed. The experimental results show that the principal stress difference-axial strain curves of coal under different stability time conditions present a periodic hysteresis loop trend, elastic modulus do not decrease with the increase of cycle numbers under stability time and external load, and damage mechanism changes. The total energy absorbed U and dissipative energy U^d change with the increase of cycle numbers in an overall trend of L, and elastic strain U^e is gradually reduced and tends to be stable. In the process of 30 cyclic loads, elastoplastic damage variables of coal based on energy calculation show a tendency of fluctuating and stable changes around a stable value.

Key words: coal, cyclic loading, energy, irreversible plastic strain, elastoplastic damage

CLC Number:

X936

ZHANG Yao, LI Bobo, REN Chonghong, XU Jiang, LI Jianhua. Energy mechanism analysis on elastoplastic damage of coal under cyclic loading[J]. China Safety Science Journal, 2020, 30(5): 88-94.

References

[1] 郭军杰,程晓阳. 循环载荷下煤样变形及声发射特征试验研究[J]. 中国安全科学学报, 2017, 27(11): 109-115.
GUO Junjie, CHENG Xiaoyang. Experimental study on deformation and acoustic emission characteristics of coal samples under cyclic loading [J]. China Safety Science Journal, 2017, 27(11): 109-115.
[2] 赵星光, 李鹏飞, 马利科, 等. 循环加、卸载条件下北山深部花岗岩损伤与扩容特性[J]. 岩石力学与工程学报, 2014, 33(9): 1 740-1 748.
ZHAO Xingguang, LI Pengfei, MA Like, et al. Damage and dilation characteristics of deep granite at Beishan under cyclic loading-unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(9): 1 740-1 748.
[3] 刘新荣, 邓志云, 刘永权, 等. 峰前循环剪切作用下岩石节理损伤特征与剪切特性试验研究[J]. 岩石力学与工程学报, 2018, 37(12): 2 664-2 675.
LIU Xinrong, DENG Zhiyun, LIU Yongquan, et al. Study on the characteristics and shear characteristics of rock arbiting damage under the action of pre-peak cycle shear[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(12): 2 664-2 675.
[4] 王向宇, 周宏伟, 钟江城, 等. 三轴循环加卸载下深部煤体损伤的能量演化和渗透特性研究[J]. 岩石力学与工程学报, 2018, 37(12): 2 676-2 684.
WANG Xiangyu, ZHOU Hongwei, ZHONG Jiangcheng, et al. Study on energy evolution and permeability characteristics of deep coal damage under triaxial cyclic loading and unloading conditions[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(12): 2 676-2 684.
[5] 李子运, 吴光, 黄天柱, 等. 三轴循环荷载作用下页岩能量演化规律及强度失效判据研究[J]. 岩石力学与工程学报, 2018, 37(3): 662-670.
LI Ziyun, WU Guang, HUANG Tianzhu, et al. Variation of energy and criteria for strength failure of shale under traixial cyclic loading[J]. Chinese Journal of Rock Mechanics and Engineering, 2018, 37(3): 662-670.
[6] SHU Ronghua, YIN Tubing, LI Xibing, et al. Effect of thermal treatment on energy dissipation of granite under cyclic impact loading[J]. Transactions of Nonferrous Metals Society of China, 2019, 29(2): 385-396.
[7] 张文清, 石必明, 穆朝民. 冲击载荷作用下煤岩破碎与耗能规律实验研究[J]. 采矿与安全工程学报, 2016, 33(2): 375-380.
ZHANG Wenqing, SHI Biming, MU Chaomin. Experimental research on failure and energy dissipation law of coal under impact load[J]. Journal of Mining & Safety Engineering, 2016, 33(2): 375-380.
[8] ZHANG Yan, FENG Xiating, ZHANG Xiwei, et al. A novel application of strain energy for fracturing process analysis of hard rock under true triaxial compression[J]. Rock Mechanics and Rock Engineering, 2019, 52(11): 4 257-4 272.
[9] 谢和平, 鞠杨, 董毓利. 经典损伤定义中的“弹性模量法”探讨[J].力学与实践, 1997, 19(2): 2-6.
XIE Heping, JU Yang, DONG Yuli. Discussion about "elastic modulus method" in the classic definition of damage[J]. Mechanics and Practice, 1997, 19(2): 2-6.
[10] XU Xiaoli, GAO Feng, ZHANG Zhizhen. Thermo-mechanical coupling damage constitutive model of rock based on the Hoek-Brown strength criterion[J]. International Journal of Damage Mechanics, 2018, 27(8): 1 213-1 230.
[11] 谢和平, 鞠杨, 黎立云, 等. 岩体变形破坏过程的能量机制[J]. 岩石力学与工程学报, 2008, 27(9): 1 729-1 740.
XIE Heping,JU Yang,LI Liyun,et al. Energy mechanism of deformation and failure of rocks masses[J]. Chinese Journal of Rock Mechanics and Engineering, 2008, 27(9): 1 729-1 740.
[12] 许江, 彭守建, 尹光志, 等. 含瓦斯煤热流固耦合三轴伺服渗流装置的研制及应用[J]. 岩石力学与工程学报, 2010, 29(5): 907-914.
XU Jiang, PENG Shoujian, YIN Guangzhi, et al. Development and application of triaxial servo-controlled seepage equipment for thermo-fluid-solid coupling of coal containing methane[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(5): 907-914.

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