An Analysis Model of UDEC for Crack Propagation and Numerical Simulations for Specimens with Double Pre-Existing Cracks
-
摘要: 针对通用离散元程序(UDEC)提出一种新的预制裂纹扩展三角形块体分析模型,首先采用有限元商业软件将关注区域剖分成由三角形单元组成的有限元网格,再用转换程序转换成UDEC分析模型,UDEC分析模型由三角形块体和模拟块体边界的节理组成,节理包括真实的节理和虚拟节理,裂纹扩展沿虚拟节理进行,虚拟节理破裂准则采用UDEC的SS节理模型,用于模拟岩石裂纹萌生、扩展、贯通。编制了转换程序,并采用预制裂纹扩展UDEC三角形块体分析模型计算三个单轴压缩应力作用下含预制双裂纹试样的裂纹扩展算例,并对模拟结果与试验结果进行对比,模拟结果的裂纹扩展规律与已有的物理试验结果基本一致,表明该算法正确有效。Abstract: An UDEC analysis model composed of triangular blocks for crack propagation was proposed. In the proposed model,a FEM mesh of triangular elements was generated in the interesting area by a finite element software first. Then the FEM mesh was converted into an UDEC mesh by a transformation program. The UDEC mesh was composed of triangular blocks and joints on the boundary of simulated blocks. The joints included virtual joints and real joints. These virtual joint interfaces provided paths along which cracks could generate and propagate. Its failure was controlled by the model of Joint model SS which was provide by UDEC. The proposed analysis model of UDEC was used for simulating the generation,propagation and coalescence of rock cracks. The transformation program of the proposed model was developed. To verify the correctness of the algorithm,three numerical examples of test samples with double parallel pre-existing cracks under uniaxial compression were computed. The simulated results were compared with the ones of existing tests. The simulated laws of crack propagation were in accordance with the phenomena observed in the tests. Those indicated that the proposed UDEC analysis model for cracks propagation was correct and effective.
-
Key words:
- rock mechanics /
- crack propagation /
- discrete element /
- UDEC /
- simulation
-
[1] 俞绍诚.水力压裂技术手册[M]. 北京:石油工业出版社, 2010. [2] 焦玉勇, 张秀丽, 刘泉声, 等.用非连续变形分析方法模拟岩石裂纹扩展[J].岩石力学与工程学报, 2007, 26(4):682-691. [3] KOMORI K.Ductile fracture criteria for simulating shear by node separation method[J].Theoretical and Applied Fracture Mechanics, 2005, 43:101-114. [4] KOMORI K.Simulation of shearing by node separation method[J].Computers and Structures, 2001, 45:197-207. [5] 唐春安, 王述红, 傅宇方. 岩石破裂过程数值试验[M]. 北京:科学出版社, 2003. [6] TANG C A, LIN P, WONG R H C, et al.Analysis of crack coalescence in rock-like materials containing three flaws: Part II: numerical approach[J]. International Journal of Rock Mechanics & Mining Sciences, 2001, 38: 925-939. [7] 张振南, 葛修润, 李永和.虚拟多维内连结键模型(VMIB)在岩石类材料单轴破坏中的应用[J].岩土工程学报, 2006, 28(4):504-509. [8] 张永彬, 唐春安, 梁正召, 等.岩石破裂过程分析系统并行计算方法研究[J].岩石力学与工程学报, 2006, 25(9):1795-1801. [9] 马文强, 王同旭.多围压脆岩压缩破坏特征及裂纹扩展规律[J].岩石力学与工程学报, 2018, 37(4):898-908. [10] KAZERANI T, ZHAO J. Micromechanical parameters in bonded particle method for modelling of brittle material failure[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2010, 34(18): 1877-1895. [11] GAO F. Simulation of failure mechanisms around underground coal mine openings using discrete element modelling[D]. Vancouver:Simon Fraser University, 2013. [12] LAN H, MARTIN C D, HU B. Effect of heterogeneity of brittle rock on micromechanical extensile behavior during compression loading[J/OL]. Journal of Geophysical Research, 2010, 115(B1): B01202[2022-10-01].https://doi.org/10.1029/2009JB006496. [13] NICKSIAR M, MARTIN C D. Factors Affecting Crack Initiation in Low Porosity Crystalline Rocks[J]. Rock Mechanics & Rock Engineering, 2014, 47(4):1165-1181. [14] GAO F, STEAD D, ELMO D. Numerical simulation of microstructure of brittle rock using a grain-breakable distinct element grain-based model[J]. Computers & Geotechnics, 2016, 78:203-217. [15] 谭鑫, HEINZ K. 含层理构造的非均质片麻岩巴西劈裂试验及离散单元法数值模拟研究[J]. 岩石力学与工程学报, 2014, 33(5):938-946. [16] 马文强, 王振慧. 均质度对脆岩压缩破坏及裂纹扩展的影响规律[J]. 信阳师范学院学报(自然科学版), 2020, 33(4):689-696. [17] YAN M. Numerical modelling of brittle fracture and step-path failure: from laboratory to rock slope scale[D]. Benaby: Simon Fraser University, 2008. [18] ZHAO C, ZHOU Y M, ZHAO C F, et al. Cracking processes and coalescence modes in rock-like specimens with two parallel pre-existing cracks[J]. Rock Mechanics and Rock Engineering, 2018, 51(11): 3377-3393. [19] 鲍如意, 赵程, 周依盟, 等. 含预制双裂纹试样岩桥贯通模式的数值研究[J]. 水利水运工程学报, 2021(4):19-28. [20] GAO F Q, STEAD D. The application of a modified Voronoi logic to brittle fracture modeling at the laboratory and field scale[J]. International Journal of Rock Mechnics and Mining Sciences, 2014, 68:1-14. [21] Itasca Consulting Group Inc. UDEC(universal distinct element code)[M].Version 4.1. Minneapolis:Itasca, 2011. [22] 朱维申, 李术才, 陈卫忠.节理岩体破坏机制和锚固效应及工程应用[M]. 北京:科学出版社, 2002.
点击查看大图
计量
- 文章访问数: 38
- HTML全文浏览量: 8
- PDF下载量: 0
- 被引次数: 0