The Fracture Induced Electromagnetic Radiation: Approach and Protocol for the Stress State Assessment for Mining

Experimental investigation on time‐frequency evolution characteristics of electromagnetic radiation below ULF reflecting the damage performance of coal or rock materials

“…15,16,[21][22][23][24] Over the last few decades, a number of researches on mechanism, characteristics, and influence factors of EMR induced by fracture of coal and rock have been conducted, mainly using theoretical, numerical, and experimental methods. [14][15][16][17]26,27 And these research results confirm that EMR accompanies the deformation and fracture process of coal and rock and can be a potential method to characterize the internal damage of coal and rock mass. Moreover, some researchers developed a variety of EMR monitoring instruments, put them into the monitoring of coal and rock dynamic disaster, and obtained good application effect.…”

“…Subsequently, many more scholars discovered the EMR during fracture process in various rocks through experiments in laboratory scale and geophysical scale 15,16,21–24 . Over the last few decades, a number of researches on mechanism, characteristics, and influence factors of EMR induced by fracture of coal and rock have been conducted, mainly using theoretical, numerical, and experimental methods 14–17,26,27 . And these research results confirm that EMR accompanies the deformation and fracture process of coal and rock and can be a potential method to characterize the internal damage of coal and rock mass.…”

“…And these research results confirm that EMR accompanies the deformation and fracture process of coal and rock and can be a potential method to characterize the internal damage of coal and rock mass. Moreover, some researchers developed a variety of EMR monitoring instruments, put them into the monitoring of coal and rock dynamic disaster, and obtained good application effect 17,24,27 . However, due to the complexity of structural damage and multiple sources of free charge generation in coal and rock materials, the mechanism of EMR generated in process of deformation and fracture is still unclear and not unified, so the application of EMR techniques lacks rigorous theoretical support, and the accuracy of prediction and early warning is insufficient.…”

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] And through the above researches, numerous health monitoring methods for detecting the deformation and fracture process of rock and rock-like materials have emerged, including acoustic emission techniques, [3][4][5][6] optical fiber sensing, 7 ultrasonic wave, 8,9 nuclear magnetic resonance techniques, 10 infrared thermal imaging techniques, 11 digital imaging and X-ray CT imaging techniques, 3,12,13 and electromagnetic radiation techniques. [14][15][16][17] Among these methods, electromagnetic radiation techniques are now widely used in the field of mining engineering for structural health monitoring due to its advantages of continuous, real time, non-contact, and so forth. The EMR phenomenon produced during material fracture was firstly discovered by Stepanov in 1933, 20 and studies on EMR in the fracture process of coal and rock originated from electromagnetic anomaly before earthquake.…”

“…Up to now, many experimental and numerical studies have been devoted to investigate the fracturing behaviors and damage evolution process of rock and rock-like materials. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] And through the above researches, numerous health monitoring methods for detecting the deformation and fracture process of rock and rock-like materials have emerged, including acoustic emission techniques, [3][4][5][6] optical fiber sensing, 7 ultrasonic wave, 8,9 nuclear magnetic resonance techniques, 10 infrared thermal imaging techniques, 11 digital imaging and X-ray CT imaging techniques, 3,12,13 and electromagnetic radiation techniques. [14][15][16][17] Among these methods, electromagnetic radiation techniques are now widely used in the field of mining engineering for structural health monitoring due to its advantages of continuous, real time, non-contact, and so forth.…”