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电磁是煤岩动力灾害预测的重要手段,掌握电磁信号特征与煤体损伤程度间的关系是灾害预测的关键.通过原煤SHPB试验及瞬变电磁监测,分析煤体冲击破裂过程中的电磁信号(0～3 kHz频段)特征,从破裂耗能及破碎程度两方面分析试件损伤特性,并探求电磁信号特征(幅值、能量)与煤体破裂损伤特性间的关系,研究发现:①分形维数与最终破裂程度规律相似,利用分形维数来定量评价煤体破裂程度是可行的;②煤岩冲击破裂电磁信号呈瞬时脉冲状,持续时间仅为微秒级,信号幅值及能量总体随着破碎程度的增大而增大;③煤岩冲击破裂电磁信号的幅值及能量与其损伤程度(分形维数)符合较好的线性关系,利用电磁信号特征监测煤岩损伤程度是可行的;④受煤岩材料固有缺陷的不确定性及共振破坏现象的影响,煤岩的损伤程度与冲击耗散能间的相关性较弱.研究成果对于利用电磁信号特征评价煤体损伤程度进而预测动力灾害的发生具有重要意义.“,”The electromagnetic technology is an important means for predicting coal or rock dynamic disasters. The relationship between characteristic of electromagnetic signals and degree of damage is the premise of accurate prediction. Through coal SHPB experiments and transient electromagnetic monitoring, the characteristics of electromagnetic signals (0～3 kHz) of coal are analyzed in the process of rupture. The damage properties are analyzed from the degree of crushing and rupture energy. Then the relationship between the characteristics of electromagnetic signals (amplitude, energy) and the properties of coal damage is studied. The results show that the laws of fractal dimension and eventual rupture degree are similar. The fractal dimension can be used to quantitatively evaluate the extent of fracture specimens. The electromagnetic signals have transient pulse characteristics, and last only a few microseconds. The amplitude and energy of signals increase with the fragmentation degree. They exhibit a good linear relationship. The characteristics of electromagnetic signals can be used to monitor the damage degree of coal. Owing to the presence of the defects of inherent uncertainty coal materials and the resonance damage phenomenon, the correlation between damage degree and rupture energy is weak. The research results are important to the evaluation of the damage degree and to the prediction of dynamic disasters of coal or rock by use of the characteristics of electromagnetic signals.