摘要
花岗岩及其他粒状结晶质岩石由于其组成的矿物形状、矿物朝向和矿物成分等细观结构的影响,表现出不连续、非均匀及各向异性等非均质特性。但现有的数值方法还不能够定量研究矿物晶粒形状及朝向的影响,为了探究矿物晶粒的形状及朝向等非均质性对岩石力学性质的影响,基于颗粒离散元法提出晶粒织构模型(GTM),其通过生成代表真实矿物晶粒的随机不规则椭圆形柔性晶粒簇(Cluster),能够定量分析矿物晶粒形状及朝向的影响并再现岩石矿物晶粒内部和晶界损伤演变的动态过程。通过与室内试验结果进行对比,经过细观参数标定后的GTM模型能够很好地模拟出LdB花岗岩在不同力学条件下的宏观力学特性及破坏特征。通过构建不同晶粒纵横比及旋转角度的GTM模型研究矿物晶粒形状及朝向的影响,发现晶粒的形状及朝向的改变会导致晶内及晶界接触比例及接触整体朝向的变化,进而影响到岩石的宏观力学特性及破坏特征。GTM模型能够更加全面真实地从岩石的细观结构角度探究岩石的力学特性与破坏机制,对于揭示岩石细观非均质性对宏观力学特性及晶内、晶界裂纹扩展的影响提供了有效的方法和手段。
Granite and other crystalline rocks exhibit heterogeneous properties such as discontinuity and anisotropy due to the microstructure such as mineral shape,mineral orientation and mineral composition.However,existing numerical methods are not able to quantitatively study the influence of mineral grain shape and orientation.In this paper,in order to investigate the influence of inhomogeneities such as shape and orientation of mineral grains on rock properties,the grain texture model(GTM)based on the particle discrete element method is proposed,GTM can investigate the influence of mineral grain shape and orientation and study the evolution of intra-and inter-grain crack of minerals by generating a random irregular shaped Cluster representing real mineral grains.By comparing with the results of experimental tests,the GTM can mimic the macroscopic mechanical properties and failure mode of LdB granite under different mechanical conditions with good agreement after the calibration of micro-parameters.By modeling GTM with various grain aspect ratios and rotation angles to investigate the influence of mineral grainshape and orientation,it is found that the change of grain shape and orientation will lead to the change of intra- andinter-grain contact ratios and orientations,which in turn affects the macroscopic mechanical properties and failuremode of the rock. The GTM can study the mechanical properties and failure mechanism of rocks more comprehensivelyfrom the perspective of microstructure of rocks,which provides an effective method to reveal the influence ofheterogeneous properties on the macroscopic mechanical properties and intra- and inter-grain crack propagation.
作者
王穗丰
赵先宇
张利平
崔臻
王涛
WANG Suifeng;ZHAO Xianyu;ZHANG Liping;CUI Zhen;WANG Tao(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan,Hubei 430072,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第10期2515-2527,共13页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金海外及港澳学者合作项目(51428902)。
关键词
岩石力学
花岗岩
晶粒织构模型
晶粒形状
晶粒朝向
力学特性
rock mechanics
granite
grain texture model
grain shape
grain orientation
mechanical properties
