Abstract
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Highlights
Coal resources play a significant role during the energy consumption, especially for industrial raw materials and electric power production [1,2,3]
Wang et al reported that coal rock materials could produce ultralow frequency (ULF) electromagnetic radiation (EMR) signals during the damage and failure processes, and the change trend of the signals was well similar to stress and acoustic emission (AE) signals [25]
Considering the direct contact between electrode and the sample surface, the electric signals from channel 8 (ch8: Figure 4(c)) were more sensitive and produced violent increase and reduction when stress fluctuated at 107 s, which was consistent with the variation trends of AE and EMR
Summary
Coal resources play a significant role during the energy consumption, especially for industrial raw materials and electric power production [1,2,3]. During the damage and failure process of the rock, acoustic emission (AE) signals are generated [12]. Wang et al investigated the features of similar material mechanics and concluded that the law of AE behavior and the characteristics of similar material fracture can obtained the regularity of stress and deformation during material loading processes [17]. Wang et al reported that coal rock materials could produce ultralow frequency (ULF) EMR signals during the damage and failure processes, and the change trend of the signals was well similar to stress and AE signals [25]. Under shear failure, the electric-magnetic-acoustic signal regularity of sandstone was studied, and the impact of sample size on experimental results was analyzed. It is promising to further reveal the dynamic disaster process of coal rock materials and perfect the EMR theory as well as the corresponding test equipment
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