Evolutionary characteristics and correlations between deformation energy and strain in anthracite coal during stress wave-induced catastrophes

Abstract

Understanding the deformation evolution process, as well as the energy storage and transformation behavior of coal under the influence of stress waves, is essential to promote technological progress and safety improvement in mining, underground engineering, and energy utilization. With the SHPB system, dynamic impact tests were conducted on anthracite coal under varying impact loads in this study. The deformation parameter characteristics of anthracite coal were examined regarding the storage and transformation patterns of deformation energy. Further analysis was performed on the attenuation laws of stress waves in the time and frequency domains. Besides, the correlation characteristics of strain and deformation energy in the stress wave disaster-causing mechanism were investigated, revealing that maximum and residual strain exhibited a notable linear relationship with impact load, with growth rates of 0.209 % and 0.212 %, respectively. Parameters ε_b and ε_h followed a down-concave exponential growth pattern and an up-concave exponential decrease pattern, respectively. W_d and W_s presented a notable linear strain rate effect, with growth rates of 2.44 and 2.30, respectively, and a significant linear energy effect, with growth rates of 0.46 and 0.44, respectively. W_b and W_h demonstrated a down-concave exponential growth pattern and an up-concave exponential decrease. The reflection and transmission effects of the stress wave in the time domain displayed clear linear growth and attenuation trends with the impact load, characterized by a growth rate of 0.020 and an attenuation rate of 0.015, respectively. Furthermore, an approximate linear increase appeared on the spectrum amplitudes of the incident, reflection, and transmission waves, with growth rates of 0.035, 0.032, and 0.0074, respectively.