平行裂隙砂岩破坏和声发射特性数值研究

    Numerical Simulation Research of Failure and Acoustic Emission Characteristics of Parallel Fractured Sandstone

    • 摘要: 为了研究加载速率对裂隙砂岩破坏特征和声发射响应的影响,利用RFPA2D数值模拟软件对单轴压缩条件下的预制平行裂纹砂岩进行模拟,分析不同加载速度下的力学特性、声发射响应特性和裂纹演化规律。结果表明:随着加载速率的增加,平行裂隙砂岩峰值强度、峰值应变、岩桥破裂强度和岩桥破裂应变都相应增大;峰值声发射计数也随着加载速率的增加而增大;当加载速率较小时,声发射信号较为丰富,试样破裂以沿预制裂纹扩展的剪切破坏为主,当加载速率较大时,声发射信号更加集中于破裂瞬间,最终的主裂纹为与加载方向平行的张拉裂纹。

       

      Abstract: In order to study the effect of loading rate on the failure characteristics and acoustic emission response of fractured sandstone, the prefabricated parallel cracked sandstone under uniaxial compression was simulated by using RFPA2D numerical simulation software. And the mechanical characteristics, acoustic emission response characteristics and crack evolution law under different loading speeds are analyzed. The results show that with the increase of loading rate, peak strength, peak strain, rock bridge strength and rock bridge fracture strain of parallel fractured sandstone increase correspondingly. Peak AE counts also increase with the increase of loading rate. When the loading rate is low, the acoustic emission signals are abundant, and the fracture of the specimen is mainly shear failure along the prefabricated crack growth. When the loading rate is high, the final main crack is a tension crack parallel to the loading direction.

       

    /

    返回文章
    返回