预制裂隙岩石裂纹扩展相场模拟方法研究  

Research on phase-field simulation method of crack propagation of rock with pre-existing fissures

作　　者：王苏生 杨圣奇 田文岭[1,2] 黄彦华 WANG Susheng;YANG Shengqi;TIAN Wenling;HUANG Yanhua(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学力学与土木工程学院,江苏徐州221116 [2]中国矿业大学、深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《岩石力学与工程学报》2023年第2期365-377,共13页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(52109143);中央高校基本科研业务费专项资金资助(2021QN1023)。

摘　　要：裂隙岩石变形破坏是其内部裂纹萌生、生长和聚合成宏观裂隙的结果。为了模拟裂隙岩石复杂断裂破坏过程,基于传统的相场断裂模型,通过拉、拉剪和压剪应变能密度分解,提出一种新的相场模型。根据Mohr-Coulomb准则分别定义剪切应力和压剪应变能,推导位移场和相场耦合控制方程,采用有限元方法进行空间离散和交错求解算法进行相场理论数值求解。通过对比基准算例的相场模拟结果与解析解,验证编制的相场有限元程序的准确性。然后,基于黄砂岩试验数据确定模型参数,运用该程序对单预制裂隙岩石(α=30°)和双预制裂隙岩石(α=30°,β=30°和α=30°,β=60°)单轴压缩试验进行模拟,再现了裂隙岩石所产生的张拉、剪切和混合裂纹生长和扩展模式,与试验结果吻合较好。因此,改进的相场模型能够模拟裂隙岩石裂纹起裂及后续扩展的动态演化过程。The deformation and failure of fissured rock are the results of the initiation,growth and coalescence of cracks into macroscopic cracks.To simulate the complicated fracture failure process of fractured rock,a new phasefield model is proposed based on the conventional phase-field fracture model by means of decompositions of the strain energy density into tensile,tensile-shear and compressive-shear parts.According to the Mohr-Coulomb criterion,the shear stress and compression-shear strain energy are individually defined.The coupling governing equations of the displacement field and phase field are derived.And the finite element method(FEM)is used for spatial discretization and the staggered algorithm is used for the numerical solution of the phase-field theory.The accuracy of the phase-field finite element program is verified by comparing the simulation results and the analytical solution of benchmark example.Then,model parameters are determined based on test data of yellow sandstone.The program is used to simulate the uniaxial compression tests of the rock containing a single fissure(α=30°)and rock containing double fissures(α=30°,β=30°and α=30°,β=60°).And the growth and propagation modes of tensile,shear and mixed cracks produced by the fissured rock are replicated,which is well consistent with the test results.Therefore,the improved phase-field model can simulate the crack initiation and crack propagation of fissured rock.

关 键 词：岩石力学 裂隙岩石 裂纹扩展 断裂破坏机制 交错求解算法 相场模拟 

分 类 号：TU45[建筑科学—岩土工程]