不同层理煤破坏过程声发射RA-AF特征研究

    RA-AF characteristics of acoustic emission in uniaxial compression failure of different bedded coal

    • 摘要: 为研究不同层理煤破坏声发射RA-AF特征,开展了0°、30°、60°、90°层理夹角煤单轴压缩破坏试验,同步采集了煤体力学和声发射数据,分析了RA-AF特征与裂纹扩展模式的关系。结果表明:第Ⅰ和第Ⅱ阶段,声发射计数水平较低,第Ⅲ阶段,计数值逐渐增加,在第Ⅳ阶段,α=0°和60°时,声发射计数更多,峰值较高;α=0°和90°时,张拉破坏占比分别为58.44%和58.06%,裂纹以张拉破坏为主;α=30°时,张拉剪切破坏占比相当,裂纹表现为张剪复合破坏;α=60°时,试样剪切破坏占比68.14%,裂纹以剪切破坏为主。

       

      Abstract: In order to study the characteristics of RA-AF of coal failure in different coal bedding, uniaxial compression failure experiments of coal with 0°, 30°, 60° and 90° bedding angles were carried out. The mechanical and AE data of coal body were collected synchronously. The relationship between the characteristics of RA-AF and crack propagation mode was analyzed. The results show that: in the Ⅰ and Ⅱ stages, the AE count level is low, in the Ⅲ stage, the AE count is gradually increased, in the Ⅳ stage, when α=0° and 60°, AE counts are more and the peak value is higher; when α=0° and 90°, the tensile failure ratio is 58.44% and 58.06%, respectively, and the tensile failure is the main crack; when α=30°, tensile failure and shear failure are the same, and the crack appears as tensile shear composite failure; when α=60°, the shear failure ratio of the sample is 68.14%, and the shear failure is the main crack.

       

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