EXPERIMENTS AND SIMULATIONS ON FRACTURE OF ROCK WITH DIFFERENT NUMBERS OF FISSURES
-
摘要: 采用岩石力学伺服试验机,对含有预制裂纹的辉石似长岩进行单轴压缩试验,分析不同裂隙数目的岩石的裂纹启裂、扩展和贯通破坏规律,并利用扩展有限元软件XFEM模拟解释分析试验现象。研究结果表明:辉石似长岩的单轴抗压强度随着裂纹数量的增加而呈线性下降;随着裂纹数量的增加,裂纹尖端位置与远离裂纹位置应变比值增加;多裂纹岩石出现次生裂纹时,试件应力达到峰值之后有应力回弹现象;对单裂纹、双裂纹、三裂纹试件的萌生、扩展及贯通过程的模拟表明,与试验岩石翼裂纹萌生、扩展破坏过程相似度较高。Abstract: Uniaxial compression experiments were conducted for pyroxenite specimens with pre-slotted fissures by the rock mechanics servo-controlled testing system. The laws of initiation, propagation and coalescence of rock specimens with different numbers of fissures were studied. The experiment phenomena were expounded by XFEM simulations. The study showed that the uniaxial compressive strength of pyroxenite specimens decreased linearly with the increase of numbers of cracks; as numbers of pre-slotted fissures increased, the rates of the strain at the pre-slotted fissure tips to that away from the pre-slotted fissures increased. When there were secondary cracks in multiple pre-slotted fissure specimens, stress would rebound after reaching the peak. The process of initiation, propagation and coalescence of specimens with a single, double or three pre-slotted fissures were simulated. The laws of crack initiation, evolution and coalescence processes obtained by numerical simulations were similar to that by tests.
-
Key words:
- compressive strength /
- crack propagation /
- crack coalescence /
- strain /
- XFEM
-
[1] LAJTAI E Z. Brittle Fracture in Compression[J]. International Journal of Fracture, 1974, 10(4):525-536. [2] REYES O, EINSTEIN H H. Failure Mechanisms of Fractured Rock-A Fracture Coalescence Model[C]//Proceedings of 7th International Congress on Rock Mechanics, 1991:333-340. [3] LI Y P, CHEN L Z, WANG Y H. Experimental Research on Precracked Marble Under Compression[J]. International Journal of Solids Struct, 2005, 42(9/10):2505-2516. [4] 张平, 贺若兰, 李宁, 等. 不同应变速率下非贯通裂隙介质的单轴抗压强度分析[J]. 岩石力学与工程学报, 2007, 26(1):2735-2742. [5] 刘泉声, 魏莱, 刘学伟. 基于Griffith强度理论的岩石裂纹起裂经验预测方法研究[J]. 岩石力学与工程学报, 2017, 36(7):1561-1569. [6] YANG S Q, JING H W. Strength Failure and Crack Coalescence Behavior of Brittle Sandstone Samples Containing a Single Fissure Under Uniaxial Compression[J]. International Journal of Fracture, 2011, 168(2):227-250. [7] BOBET A, EINSTEIN HH. Fracture Coalescence in Rock-Type Materials Under Uniaxial and Biaxial Compression[J]. International Journal of Rock Mechanics and Mining Sciences, 1998, 35(7):863-888. [8] WONG R H C, CHAU K T. Crack Coalescence in a Rock-Like Material Contain Two Cracks[J]. International Journal of Rock Mechanics & Mining Sciences, 1998, 35(2):147-164. [9] WONG R H C, CHAU K T, TANG C A, et al. Analysis of Crack Coalescence in Rock-Like Materials Containing Three Flaws-Part I:Experimental Approach[J]. International Journal of Rock Mechanics & Mining Sciences, 2001, 38(7):909-924. [10] PARK C H, BOBET A. Crack Coalescence in Specimens with Open and Closed Flaws:A comparison[J]. International Journal of Rock Mechanics & Mining Sciences, 2009, 46(5):819-829. [11] 黄明利, 唐春安, 朱万成. 岩石破裂过程的数值模拟研究[J]. 岩石力学与工程学报, 2000, 19(4):468-471. [12] 周小平, 杨海清, 董捷. 压应力状态下多裂纹扩展过程数值模拟[J]. 岩石力学与工程学报, 2010, 34(2):192-197. [13] WANG Y T, ZHOU X P, XU X. Numerical Simulation of Propagation and Coalescence of Flaws in Rock Materials Under Compressive Loads Using the Extended Non-Ordinary State-Based Peridynamics[J]. Engineering Fracture Mechanics, 2016, 163:248-273. [14] 杨圣奇, 戴永浩, 韩立军,等. 断续预制裂隙脆性大理岩变形破坏特性单轴压缩试验研究[J]. 岩石力学与工程学报, 2009, 28(12):2391-2404.
点击查看大图
计量
- 文章访问数: 83
- HTML全文浏览量: 18
- PDF下载量: 0
- 被引次数: 0