Numerical Simulation of Crack Propagation in Rock by Particle Flow Code
Numerical Simulation of Crack Propagation in Rock by Particle Flow Code
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岩石裂纹扩展的粒子流数值模拟
DOI：
10.2473/journalofmmij.124.611
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Furuzumi
中科院分区：
文献类型：
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作者：
N. Kamoshida;M. Okawara;Masayoshi Abe;M. Furuzumi
岩石中的裂纹扩展会影响岩体结构的稳定性。为了设计合适的加固或支撑系统，预测岩石中的裂纹扩展非常重要。因此，作者重点研究基于不连续介质力学的离散元方法。在该方法中，材料被表示为刚性圆形颗粒的集合体，输入参数不是材料的力学性能，例如杨氏模量和泊松比，而是与每个颗粒相关的微观参数。本文首先介绍了利用粒子流程序（PFC2D）对单轴压缩试验和巴西试验进行数值模拟，以确定Kimachi砂岩合适的微观参数。单轴压缩试验得到的应力-应变曲线和巴西试验得到的拉伸应力-轴向应变曲线表明，该模型采用团块模型，不仅可以表示单轴压缩强度、杨氏模量、泊松比，还可以表示拉伸强度。然后利用半圆弯曲(SCB)试件进行I型、II型和混合模式断裂韧性测试的数值模拟。将模拟结果与实验数据进行比较。发现数值模拟与实验得到的断裂韧性值差异在10%以内。数值模拟的破坏面位置与实验观察结果吻合较好。总之，粒子流代码可以模拟岩石的抗裂性能和裂纹扩展方向。
Crack propagations in rock will affect stability of rockmass structures. It is important to predict the crack propagation in rock in order to design the suitable reinforcement or support system. Therefore, authors focus on a distinct element method based on discontinuum mechanics. In this method, a material is expressed as assemblies of rigid circular particles, and input parameters are not mechanical properties of the material, such as Young's modulus and Poisson's ratio, but microscopic parameters related to each particle. This paper firstly describes the numerical simulation using Particle Flow Code (PFC2D) of uniaxial compressive test and Brazilian test so as to determine the proper microscopic parameters of Kimachi sandstone. Stress-strain curves obtained from the uniaxial compressive tests and tensile stress-axial strain curves obtained from the Brazilian tests show that the model can represent not only uniaxial compressive strength, Young's modulus, Poisson's ratio, but also tensile strength, by adopting the clump model. And then numerical simulations of mode I, mode II, and mixed mode fracture toughness testing using Semi-Circular Bend (SCB) specimen are conducted. The results of the simulation are compared with the experimental data. It is found that the differences of the fracture toughness values obtained by the numerical simulation and experiments are within 10%. The locations of the failure plane by the numerical simulation are good agreement with that observed by experiments. In conclusion, the Particle Flow Code can simulate both crack resistance properties and direction of the crack propagation in rock.