THERMAL SCIENCE

International Scientific Journal

Yi-Qiang Lu

,

Xiao-Hui Liu

,

Jing Xie

,

Zhi-Qiang He

,

Cong Li

THE ENERGY EVOLUTION CHARACTERISTICS OF COAL UNDER DIFFERENT DYNAMIC STRAIN RATES AND CONFINING PRESSURES

ABSTRACT
Coal specimens from baijiao coal mine were impacted by a split Hopkinson pressure bar to study its dynamic mechanical behavior under different confining pressures (0-12 MPa) and different strain rates (20-250 s-1). The performances and the energy evolution characteristics of the coal specimens were analyzed. The results show that the strengthening effect and toughening effect of rock are gradually enhanced with the increase of confining pressure. At the same time, the coal failure gradually transitions and develops from tensile failure to compression-shear failure under the action of confining pressure. The peak strength and peak strain of coal rock show significant strain rate correlation and strong confining pressure effect with the change of confining pressures and strain rates. The dynamic strength growth factor of coal is approximately linear with the increasing of strain rates. The energy density and energy absorption density increase linearly with the increase of strain rates, and the energy consumption ratio has a logarithmic growth relationship with the strain rates.
KEYWORDS
coal, split Hopkinson pressure bar (SHPB), confining pressure, strain rate
PAPER SUBMITTED: 2018-08-10
PAPER REVISED: 2018-08-29
PAPER ACCEPTED: 2018-12-10
PUBLISHED ONLINE: 2019-05-26
DOI REFERENCE: https://doi.org/10.2298/TSCI180810205L
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Issue 3, PAGES [1409 - 1416]
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The energy evolution characteristics of coal under different dynamic strain rates and confining pressures

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence