拉伸试验中充填体声发射特性及数值模拟研究

Acoustic emission characteristics for filling body during tensile tests and its numerical simulation

  • 摘要: 下向胶结充填采矿过程中, 胶结充填体顶板的破坏不仅受抗压强度的影响, 而且还表现为张拉破坏, 为了充分探索充填体顶板张拉破坏过程中的损伤演化规律, 对胶结充填体试件进行了单轴抗拉破坏声发射试验, 并利用RFPA2D软件对其拉伸破坏过程及声发射信号进行了数值模拟.模拟分析表明, 胶结充填体的抗拉破坏是始于试件圆盘中部, 沿着加载轴线方向出现裂隙萌生与扩展, 并汇聚成宏观的裂隙带, 最终导致整体失稳的破坏过程.模拟结果还再现了抗拉破坏时声发射的分布规律, 其结果对比室内试验的声发射特征规律, 具有很好的一致性.

     

    Abstract: The roof cemented backfill damage is affected by compressive strength and tensile failure in the underhand stoping with cemented filling process. Uniaxial tensile member damage tests are performed to monitor the whole process of cementing backfill test by using acoustic emission technique to explore cemented backfill roof tensile failure during the evolution of damage law. RFPA2D software is applied to simulate cemented filling on tensile failure and acoustic emission signals. The simulation results show consolidated cemented backfill in the tensile specimen is central disc with the loading axis direction appearing cracked initiation. Extension and gathered into macro fracture zone and eventually lead to the overall loss of failure process.The simulation results represent the distribution of acoustic emission during tensile failure with favorable consistency compared with indoor test results of acoustic emission characteristics. That can simulate the damage evolution more accurate rules when the tensile strength of cemented backfill damage by using the numerical simulation analysis software--RFPA2D. It provides a theoretical basis for using acoustic emission technology as the monitoring of consolidated filling body damage.

     

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