煤岩受载变形破坏声电信号时域特征的实验

Experimental on Time Domain Characteristics of Electric Signal Emitted from Fracture of Loading Coal or Rock

受载煤岩变形破坏会产生声发射和电磁辐射信号,利用声电信号前兆在时间上和空间上的变化特征可以预警由大范围煤岩失稳引起的煤岩动力灾害。如何将声电信号的时域特征与煤岩变形破坏过程联系起来,关系到煤岩动力灾害声电预警的效果。利用煤岩单轴压缩变形破坏声电效应实验系统,测试了单轴压缩条件下煤岩试样变形破坏过程的电磁辐射和声发射信号,统计并分析了不同加载阶段电磁辐射和声发射信号的能量、脉冲等参数的变化特征。研究结果表明,受载煤岩声发射和电磁辐射的脉冲数和能量值均具有良好的时域特征;煤样的声电信号随着加载时间的进行而增大,在破坏阶段达到最大值;岩样的声发射信号在破坏阶段达到峰值而电磁辐射信号在弹塑性阶段达到峰值。

The Deformation and fracture of loading coal or rock will produce acoustic emission（ AE） and electromagnetic radiation（ EMR） signals,so we can use the time and space characteristic of the precursory AE and EMR signals to warn coal and rock dynamic disaster induced by the fracture of a large range of coal or rock. It is the key of coal and rock dynamic disaster warning by AE and EMR signals effectively that how to integrate the time characteristics of AE and EMR signals with the damage process of coal and rock loading. In this article,we use the experimental system to test AE and EMR signals of coal or rock samples during deformation and fracture under uniaxial compression,and analyze the characteristics of EMR and AE signals pulse and energy in different loading stages by statistical method. It is shown that EMR and AE signals pulse and energy of loading coal or rock samples have obvious time characteristics,but are different; the value of AE and EMR signals of coal samples increase with the loading time and it reaches the maximum at the stage of the failure; the value of AE signals of rock samples reach the maximum at the stage of the failure while the value of EMR signals reach the maximum at the elastic- plastic stage.