Citation

Zhang Y, Li B, Ren C, Xu J, Li J. China Saf. Sci. J. 2020; 30(5): 88-94.

Copyright

(Copyright © 2020, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2020.05.014

PMID

unavailable

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 Ud change with the increase of cycle numbers in an overall trend of L, and elastic strain Ue 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. © 2020 China Safety Science Journal. All rights reserved.

Language: zh