| 不同围压时含孔洞模型裂缝扩展的 连续—非连续数值模拟 |
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| 引用本文： | 白雪元,王学滨,马冰,芦伟男,祝铭泽.不同围压时含孔洞模型裂缝扩展的 连续—非连续数值模拟[J].地质力学学报,2019,25(2):240-248. |
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| 作者姓名： | 白雪元 王学滨 马冰 芦伟男 祝铭泽 |
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| 作者单位： | 辽宁工程技术大学力学与工程学院,辽宁 阜新,123000;辽宁工程技术大学计算力学研究所,辽宁 阜新,123000 |
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| 基金项目： | 国家自然科学基金项目（51574144）；辽宁省百千万人才工程项目（2017） |
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| 摘 要： | 为了有效地模拟连续介质向非连续介质的转化，发展了一种拉格朗日元方法、变形体离散元方法及虚拟裂纹模型耦合且考虑四边形单元沿对角线开裂的连续—非连续方法。利用该方法，模拟了不同围压时含孔洞模型的变形—开裂过程，统计了拉裂缝及剪裂缝区段数目，监测了一些单元的最大主应力。研究结果表明:当围压较小时，初始拉裂缝首先出现在孔洞的顶、底部，然后向模型的上、下端扩展，在初始拉裂缝的左、右两侧的拉应力集中区中产生远场拉裂缝，随后在孔洞的左、右两侧出现剪裂缝，最后，剪裂缝贯穿模型；当围压较大时，远场拉裂缝数量较少，未充分发展，远场拉裂缝与剪裂缝的发展阶段的界限不分明。含孔洞模型的最大承载力的下降是由于孔洞左、右两侧的剪裂缝向外扩展造成的。随着围压的增加，开始出现初始拉裂缝的时步数目增大，初始拉裂缝两侧的远场拉裂缝数目变少、出现变晚。
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| 关 键 词： | 连续—非连续方法 含孔洞模型 远场裂缝 应力分布 变形—开裂过程 |
| 收稿时间： | 2018/2/12 0:00:00 |
| 修稿时间： | 2018/8/3 0:00:00 |
SIMULATION OF THE CRACK PROPAGATION FOR THE MODEL WITH A HOLE UNDER DIFFERENT CONFINING PRESSURES BASED ON A CONTINUUM-DISCONTINUUM METHOD |
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| BAI Xueyuan,WANG Xuebin,MA Bing,LU Weinan and ZHU Mingze.SIMULATION OF THE CRACK PROPAGATION FOR THE MODEL WITH A HOLE UNDER DIFFERENT CONFINING PRESSURES BASED ON A CONTINUUM-DISCONTINUUM METHOD[J].Journal of Geomechanics,2019,25(2):240-248. |
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| Authors: | BAI Xueyuan WANG Xuebin MA Bing LU Weinan and ZHU Mingze |
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| Institution: | 1.College of Mechanics and Engineering, Liaoning Technical University, Fuxin 123000, Liaoning, China2.Institute of Computational Mechanics, Liaoning Technical University, Fuxin 123000, Liaoning, China |
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| Abstract: | To effectively simulate the transition process from continuum medium to discontinuum medium, a continuum-discontinuum method was developed, which is a combination of the Lagrangian element method, the deformational discrete element method and the fictitious crack method. In this method, the cracking along the diagonal line of the quadrilateral element is taken into consideration. Deformation-cracking processes of the models with a hole under different confining pressures were simulated through this method. The number of tensile and shear crack segments was calculated, and the maximum principal stresses for some elements were monitored. The following results are found. At the low confining pressure, the initial tensile cracks first appear at the roof and floor of the hole, and then they extend towards the top and bottom of the model respectively. At both sides of the initial tensile cracks, remote tensile cracks appear in tensile stress concentration zones, and then shear cracks appear at both sides of the hole; finally, shear cracks go through the model. At high confining pressure, few remote tensile cracks are found, and the dividing line between the stage of remote tensile crack propagation and the stage of shear crack propagation is not clear. The decrease of the maximum carrying capacity is due to shear crack propagation at the both sides of the hole. With an increase of the confining pressure, the number of timesteps of the initial tensile cracks increases, while that of the remote tensile cracks at both sides of the initial tensile cracks decreases and it takes more time for them to appear. |
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| Keywords: | continuum-discontinuum method model with a hole remote crack stress distribution deformation-cracking process |
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