Qin Yan, Liu Chun, Zhang Xiaoyu, Wang Xingang, Shi Bin, Wang Yue, Deng Shang
School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.
Nanjing University (Suzhou) High-Tech Institute, Suzhou, 215123, China.
Sci Rep. 2021 Feb 26;11(1):4753. doi: 10.1038/s41598-021-84224-7.
Based on a new elastic clump model, a flexible membrane is proposed for the discrete element numerical simulations of triaxial tests. Conversional triaxial tests of sandstone under the confining pressures of 2 MPa and 8 MPa were carried out, in order to validate the effectiveness of the proposed numerical simulation method. The numerical model is validated by comparing the numerical results with the test results. The deformation and failure process of numerical model is analyzed by stress-strain curves, micro fractures, displacement fields, stress fields and energy fields. The model shows an X-shape shear failure zone, of which the angle is very close to that of the test; the dip angle of most shear fractures is close to the angle of the internal friction; and there is a large amount of slipping frictional heat generated on the failure surface. During the loading process, the stress chain and stress concentration appear in the middle of the model, which lead to displacement zoning in the model. The failure of the model is associated with the growth of the micro tensile- and shear fractures. This study provides an effective tool for the macro-micro investigation of rock failure processes.
基于一种新的弹性团块模型，提出了一种用于三轴试验离散元数值模拟的柔性膜。进行了围压分别为2MPa和8MPa的砂岩常规三轴试验，以验证所提出数值模拟方法的有效性。通过将数值结果与试验结果进行比较，验证了数值模型。通过应力 - 应变曲线、微裂缝、位移场、应力场和能量场分析了数值模型的变形和破坏过程。模型显示出X形剪切破坏带，其角度与试验角度非常接近；大多数剪切裂缝的倾角接近内摩擦角；并且在破坏面上产生了大量的滑动摩擦热。在加载过程中，应力链和应力集中出现在模型中部，导致模型中出现位移分区。模型的破坏与微拉裂缝和剪切裂缝的扩展有关。本研究为岩石破坏过程的宏细观研究提供了一种有效工具。
