受载复合煤岩变形破裂电磁辐射中频信号规律试验研究

Experimental study on regularity of electromagnetic emission intermediate frequency signals in deformation and fracture of composite coal-rock under load

采用自主研制的电磁辐射采集系统,深入研究受载复合煤岩变形破裂电磁辐射中频信号特性。在前置部分的天线和电缆之间加入巴伦,把从振子流过电缆屏蔽层外皮的高频电流截断,减小信号的传输损耗,提取电磁辐射信号,分析其在加载各个阶段的分布规律和特征。结果表明:复合煤岩受载破裂释放的电磁辐射能量主要集中于500 k Hz^1 MHz中频段,电磁辐射信号整体与应力相关性较高,相关系数大于0.8。

The characteristics of electromagnetic emission（ EME） intermediate frequency signals in deformation and fracture of composite coal- rock under load were studied by using the self- developed electromagnetic emission collection system.The balun was joined between the antenna and the cable in the front portion,and the high frequency current flowing from the transducer through the cable shield sheath was cut off,then the transmission loss of signal was reduced. The EME signals were extracted to analyze the distribution regularity and characteristics in various stages of loading. The results showed that EME energy released by fracture of composite coal- rock under load was mainly concentrated on the 500 k Hz - 1 MHz intermediate frequency band. The correlation between overall EME signals and stress was high,and the correlation coefficient was larger than 0. 8.