Effect of heterogeneity of brittle rock on micromechanical extensile behavior during compression loading
Effect of heterogeneity of brittle rock on micromechanical extensile behavior during compression loading
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DOI：
10.1029/2009jb006496
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发表时间：
2010-01-26
影响因子：
3.9
通讯作者：
Hu, Bo
中科院分区：
文献类型：
--
作者：
Lan, Hengxing;Martin, C. Derek;Hu, Bo
为了模拟脆性岩石的微观结构，建立了基于晶粒的通用离散元代码模型，生成了可变形的多边形类晶粒结构。它考虑了颗粒尺度的非均质性，包括微观几何非均质性、颗粒尺度的弹性非均质性和微接触非均质性。微观几何非均质性可以用来匹配岩石的粒度分布。离散元法能够模拟由弹性变化和接触刚度各向异性引起的微观非均质性。利用Lac du Bonnet花岗岩和A“Aspo”闪长岩对建模方法进行了评价。在单轴压缩加载下，细观非均质性对细观力学行为和宏观响应都起着重要的控制作用。发现裂纹起裂应力主要受微尺度几何非均质性控制，而微接触非均质性控制强度特性。研究了非均质性对拉伸应力和相关扩展裂纹的分布和演化的影响。
A grain-based Universal Distinct Element Code model was developed to generate a deformable polygonal grain-like structure to simulate the microstructure of brittle rock. It takes into account grain-scale heterogeneity including microgeometric heterogeneity, grain-scale elastic heterogeneity, and microcontact heterogeneity. The microgeometric heterogeneity can be used to match the grain size distribution of the rock. The discrete element approach is able to simulate the microheterogeneity caused by elastic variation and contact stiffness anisotropy. The modeling approach was evaluated using Lac du Bonnet granite and A "Aspo" Diorite. The microheterogeneity played an important role in controlling both the micromechanical behavior and the macroscopic response when subjected to uniaxial compression loading. The crack-initiation stress was found to be controlled primarily by the microscale geometric heterogeneity, while the microcontact heterogeneity controlled the strength characteristics. The effect of heterogeneity on the distribution and evolution of tensile stresses and associated extension cracks was also examined.