动载作用下煤体损伤特性的电磁显现特征
发布时间：2018-11-26 10:30
【摘要】：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 k Hz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。
[Abstract]:Electromagnetic is an important means to predict coal and rock dynamic disasters. It is the key of disaster prediction to master the relationship between electromagnetic signal characteristics and the degree of coal damage. Based on the SHPB test of raw coal and transient electromagnetic monitoring, the characteristics of electromagnetic signal (0 ~ 3 k Hz band) in the process of coal impact fracture are analyzed. The damage characteristics of the specimen are analyzed from two aspects of energy consumption and breaking degree, and the characteristics of electromagnetic signal (amplitude) are explored. The relationship between energy) and the fracture damage characteristics of coal body is studied. It is found that: (1) the fractal dimension is similar to the law of final rupture degree, it is feasible to use fractal dimension to quantitatively evaluate the fracture degree of coal body; (2) the electromagnetic signal of impact fracture of coal and rock is transient pulse, the duration is only microsecond, the amplitude and energy of the signal increase with the increase of breaking degree; (3) the amplitude and energy of the electromagnetic signal of coal and rock impact fracture are in good linear relation with its damage degree (fractal dimension). It is feasible to monitor the damage degree of coal and rock by using the characteristics of electromagnetic signal. (4) due to the uncertainty of the inherent defects of coal and rock materials and the phenomenon of resonance failure, the correlation between the damage degree of coal and rock and the energy dissipation of impact is weak. The research results are of great significance for evaluating the damage degree of coal body and predicting the occurrence of dynamic disaster by using the characteristics of electromagnetic signals.
【作者单位】： 福州大学环境与资源学院;中国矿业大学(北京)资源与安全工程学院;
【基金】：国家自然科学基金项目(51604083) 福州大学贵重仪器设备开放测试基金项目(2017T018)
【分类号】：TD311
本文编号：2358317
[Abstract]:Electromagnetic is an important means to predict coal and rock dynamic disasters. It is the key of disaster prediction to master the relationship between electromagnetic signal characteristics and the degree of coal damage. Based on the SHPB test of raw coal and transient electromagnetic monitoring, the characteristics of electromagnetic signal (0 ~ 3 k Hz band) in the process of coal impact fracture are analyzed. The damage characteristics of the specimen are analyzed from two aspects of energy consumption and breaking degree, and the characteristics of electromagnetic signal (amplitude) are explored. The relationship between energy) and the fracture damage characteristics of coal body is studied. It is found that: (1) the fractal dimension is similar to the law of final rupture degree, it is feasible to use fractal dimension to quantitatively evaluate the fracture degree of coal body; (2) the electromagnetic signal of impact fracture of coal and rock is transient pulse, the duration is only microsecond, the amplitude and energy of the signal increase with the increase of breaking degree; (3) the amplitude and energy of the electromagnetic signal of coal and rock impact fracture are in good linear relation with its damage degree (fractal dimension). It is feasible to monitor the damage degree of coal and rock by using the characteristics of electromagnetic signal. (4) due to the uncertainty of the inherent defects of coal and rock materials and the phenomenon of resonance failure, the correlation between the damage degree of coal and rock and the energy dissipation of impact is weak. The research results are of great significance for evaluating the damage degree of coal body and predicting the occurrence of dynamic disaster by using the characteristics of electromagnetic signals.
【作者单位】： 福州大学环境与资源学院;中国矿业大学(北京)资源与安全工程学院;
【基金】：国家自然科学基金项目(51604083) 福州大学贵重仪器设备开放测试基金项目(2017T018)
【分类号】：TD311
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