冲击载荷下煤体动力学性能及电磁信号变化特征研究
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摘要
为了揭示突出煤层煤体动力学性能及电磁信号变化特征,利用截面为50 mm的SHPB杆技术对煤试样在冲击荷载作用下的动态力学性能进行了研究。研究表明:随着应变率的增加,煤材料的动态响应由硬化向软化过渡,煤试样破坏过程中释放的电磁信号持续时间小于1 s,频率在0～40 Hz之间,电磁信号表现为直线上升,指数下降,末尾小幅振荡的特征,且随着冲击速度、平均应变率、最大应变率等参数的增大均出现增大趋势,而随着破坏应变的增加而减小。
In order to reveal the dynamic properties and electromagnetic signal variation characteristics of outburst coal seam, the dynamic mechanical properties of coal samples under impact loading were studied by using SHPB bar technology with a cross section of 50 mm. The results show that with the increase of strain rate, the dynamic response of coal materials transits from hardening to softening, and the coal samples are destroyed. The electromagnetic signal released during the process lasts less than1 second and its frequency ranges from 0 Hz to 40 Hz. The electromagnetic signal shows the characteristics of straight-line rise,exponential decline and small oscillation at the end, and increases with the increase of impact velocity, average strain rate and maximum strain rate, while decreases with the increase of failure strain.
In order to reveal the dynamic properties and electromagnetic signal variation characteristics of outburst coal seam, the dynamic mechanical properties of coal samples under impact loading were studied by using SHPB bar technology with a cross section of 50 mm. The results show that with the increase of strain rate, the dynamic response of coal materials transits from hardening to softening, and the coal samples are destroyed. The electromagnetic signal released during the process lasts less than1 second and its frequency ranges from 0 Hz to 40 Hz. The electromagnetic signal shows the characteristics of straight-line rise,exponential decline and small oscillation at the end, and increases with the increase of impact velocity, average strain rate and maximum strain rate, while decreases with the increase of failure strain.
引文
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[2]李希勇,张修峰.典型深部重大冲击地压事故原因分析及防治对策[J].煤炭科学技术,2003,31(2):15.
[3]黄理兴.我国岩石动力学研究状况与发展[J].岩石力学与工程学报,2003,22(11):1881-1886.
[4]黄理兴.岩石动力学研究成就与趋势[J].岩土力学,2011,32(10):2889-2900.
[5]翟越.岩石类材料的动态性能研究[D].西安:长安大学,2008.
[6]李夕兵,古德生.岩石冲击动力学[M].长沙:中南工业大学出版社,1994.
[7]李成武,解北京.基于HHT法的煤冲击破坏SHPB测试信号去噪[J].煤炭学报,2012,37(11):1796-1802.
[8]李成武,解北京,杨威,等.煤冲击破坏过程中的近距离瞬变磁场变化特征研究[J].岩石力学与工程学报,2012,31(5):973-981.
[9]刘晓辉,张茹.不同应变率下煤岩冲击动力试验研究[J].煤炭学报,2012,37(9):1528-1534.
[10]付玉凯,解北京,王启飞.煤的动态力学本构模型[J].煤炭学报,2013,38(10):1169-1774.