工程科学学报，第41卷，第8期：997-1006,2019年8月 Chinese Journal of Engineering,Vol.41,No.8:997-1006,August 2019 DOI:10.13374/j.issn2095-9389.2019.08.005;http://journals.ustb.edu.cn 玄武岩三维细观孔隙模型重构与直接拉伸数值试验 郎颗娴12)，梁正召12)，董卓12) 1)大连理工大学海岸和近海工程国家重点实验室，大连1160242)大连理工大学岩石破裂与失稳研究所，大连116024 ☒通信作者，E-mail:LiangZZ@dlut.cdu.cm 摘要由于岩石材料的不透明性和多孔隙特性，通过传统的物理试验或数值模拟很难真实体现其内部三维细观结构.本文 基于CT扫描技术、边缘检测算法、滤波算法、三维点阵映射与重构算法，构建了可以表征玄武岩试样内部孔隙结构的三维细 观非均匀数值模型.结合并行计算进行直接拉伸数值试验，研究了内部孔隙结构特征对试样破坏机制及抗拉强度的影响.研 究结果表明：加载初期在试样孔隙处产生初始裂纹，随着荷载的增加初始裂纹逐渐沿横向扩展最终形成宏观拉伸破坏裂纹， 并且孔隙含量和分布位置对试样拉伸断裂的位置具有重要影响.随着孔隙率增高，试样破坏过程中的声发射数目和能量逐渐 减小.拉伸破坏模式呈现脆性破坏特征，同时孔隙的存在削弱了试样的抗拉强度 关键词玄武岩：孔隙；CT扫描：数字图像处理：有限元 分类号TG142.71 Three-dimensional microscopic model reconstruction of basalt and numerical direct tension tests LANG Ying-xian'),LIANG Zheng-zhao DONG Zhuo2) 1)State Key Laboratory of Coastal and Offshore Engineering.Dalian University of Technology,Dalian 116024,China 2)Institute of Rock Instability Seismicity Research,Dalian University of Technology,Dalian 116024,China XCorresponding author,E-mail:Liangzz@dlut.edu.cn ABSTRACT The presence of discontinuities and randomly distributed pores in basalt specimens greatly affects their engineering properties,such as the failure mechanism and strength.Therefore,investigating the mechanical and fracture behaviors of basalt affect- ed by the pre-existing defects is important for underground engineering,mining engineering,foundation engineering,and rock breaking and blasting.Laboratory tests have been widely used to research the failure mechanism of rocks under different conditions.However,it is difficult to clearly show the internal or spatial crack evolution during rock failure process in laboratory tests.Recently,X-ray comput- erized tomography (CT)and numerical tests have been used to detect the internal microstructures of rock specimens and to study their failure mechanism and strength.In addition,tensile strength is an important mechanical property of rock material.The direct tensile test is theoretically the simplest and most effective method for understanding the tensile behavior of rock.However,it is difficult to car- ry out in practical condition,because the sample processing and test procedures are complicated,also the experimental process of each sample cannot be repeated and has limited results.Due to the opacity of rocks,it is difficult to examine the three-dimensional internal structures of rocks through traditional physical and numerical experiments.In the present research,a 3D numerical method was pro- posed for simulating porous rock failure based on CT technology,the edge detection algorithm,filtering algorithm,and 3D matrix map- ping method.Direct tensile tests were carried out based on the parallel finite element method to study the effect of the porosity and pore distribution on the failure mechanism and tensile strength.The results indicate that initial cracks at the beginning of loading usually oc- cur in pores,and then with the raising of load the initial cracks propagate along the direction perpendicular to the loading direction and 收稿日期：2018-07-18 基金项目：国家重点研发计划资助项目(2016YFB0201000):国家自然科学基金资助项目(51779031,51878190)工程科学学报,第 41 卷,第 8 期:997鄄鄄1006,2019 年 8 月 Chinese Journal of Engineering, Vol. 41, No. 8: 997鄄鄄1006, August 2019 DOI: 10. 13374 / j. issn2095鄄鄄9389. 2019. 08. 005; http: / / journals. ustb. edu. cn 玄武岩三维细观孔隙模型重构与直接拉伸数值试验 郎颖娴1,2) , 梁正召1,2) 苣 , 董 卓1,2) 1) 大连理工大学海岸和近海工程国家重点实验室, 大连 116024 2) 大连理工大学岩石破裂与失稳研究所, 大连 116024 苣通信作者, E鄄mail: LiangZZ@ dlut. edu. cn 摘 要 由于岩石材料的不透明性和多孔隙特性,通过传统的物理试验或数值模拟很难真实体现其内部三维细观结构. 本文 基于 CT 扫描技术、边缘检测算法、滤波算法、三维点阵映射与重构算法,构建了可以表征玄武岩试样内部孔隙结构的三维细 观非均匀数值模型. 结合并行计算进行直接拉伸数值试验,研究了内部孔隙结构特征对试样破坏机制及抗拉强度的影响. 研 究结果表明:加载初期在试样孔隙处产生初始裂纹,随着荷载的增加初始裂纹逐渐沿横向扩展最终形成宏观拉伸破坏裂纹, 并且孔隙含量和分布位置对试样拉伸断裂的位置具有重要影响. 随着孔隙率增高,试样破坏过程中的声发射数目和能量逐渐 减小. 拉伸破坏模式呈现脆性破坏特征,同时孔隙的存在削弱了试样的抗拉强度. 关键词 玄武岩; 孔隙; CT 扫描; 数字图像处理; 有限元 分类号 TG142郾 71 收稿日期: 2018鄄鄄07鄄鄄18 基金项目: 国家重点研发计划资助项目(2016YFB0201000);国家自然科学基金资助项目(51779031,51878190) Three鄄dimensional microscopic model reconstruction of basalt and numerical direct tension tests LANG Ying鄄xian 1,2) , LIANG Zheng鄄zhao 1,2) 苣 , DONG Zhuo 1,2) 1) State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China 2) Institute of Rock Instability & Seismicity Research, Dalian University of Technology, Dalian 116024, China 苣Corresponding author, E鄄mail: LiangZZ@ dlut. edu. cn ABSTRACT The presence of discontinuities and randomly distributed pores in basalt specimens greatly affects their engineering properties, such as the failure mechanism and strength. Therefore, investigating the mechanical and fracture behaviors of basalt affect鄄 ed by the pre鄄existing defects is important for underground engineering, mining engineering, foundation engineering, and rock breaking and blasting. Laboratory tests have been widely used to research the failure mechanism of rocks under different conditions. However, it is difficult to clearly show the internal or spatial crack evolution during rock failure process in laboratory tests. Recently, X鄄ray comput鄄 erized tomography (CT) and numerical tests have been used to detect the internal microstructures of rock specimens and to study their failure mechanism and strength. In addition, tensile strength is an important mechanical property of rock material. The direct tensile test is theoretically the simplest and most effective method for understanding the tensile behavior of rock. However, it is difficult to car鄄 ry out in practical condition, because the sample processing and test procedures are complicated, also the experimental process of each sample cannot be repeated and has limited results. Due to the opacity of rocks, it is difficult to examine the three鄄dimensional internal structures of rocks through traditional physical and numerical experiments. In the present research, a 3D numerical method was pro鄄 posed for simulating porous rock failure based on CT technology, the edge detection algorithm, filtering algorithm, and 3D matrix map鄄 ping method. Direct tensile tests were carried out based on the parallel finite element method to study the effect of the porosity and pore distribution on the failure mechanism and tensile strength. The results indicate that initial cracks at the beginning of loading usually oc鄄 cur in pores, and then with the raising of load the initial cracks propagate along the direction perpendicular to the loading direction and