Study on damage-energy evolution characteristics of coal under triaxial stress

doi:10.16265/j.cnki.issn1003-3033.2019.10.015

Abstract

Abstract: In order to prevent coal dynamic disasters effectively, triaxial servo-controlled seepage equipment of thermo-fluid-solid coupling was used for a triaxial compression test of coal to study its deformation and failure characteristics under triaxial stress and mechanism of energy evolution in process of damage. Then, a constitutive model of coal damage was established and mathematical expression of damage-energy coupling was constructed. The experimental results show that change trend of partial stress-strain curve of coal under different confining pressure is basically consistent. Its energy conversion form shows a periodic change in accordance with deformation and failure rules. Confining pressure has a great influence on energy consumption characteristics, since as it increases, the growth rate of total energy absorbed by coal, elastic performance and dissipation energy will also increase, and at peak partial stress point, with its increase, total energy, storage limit and dissipation energy of critical failure point would increase linearly. Energy dissipation is the main cause of damage to internal structure of coal, and it will change in an S type with an increase of damage variables.

Key words: triaxial stress, coal damage, mechanical characteristics, constitutive model, energy characteristics

CLC Number:

X936

LI Bobo, ZHANG Yao, REN Chonghong, YANG Kang, LI Jianhua, XU Jiang. Study on damage-energy evolution characteristics of coal under triaxial stress[J]. China Safety Science Journal, 2019, 29(10): 98-104.

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