岩石类材料裂隙形成和扩展的相场方法模拟

A PHASE FIELD METHOD TO SIMULATE CRACK NUCLEATION AND CRACK PROPAGATION IN ROCK-LIKE MATERIALS

  • 摘要: 相场方法通过定义一个连续分布函数来近似表示自由不连续裂纹,在此基础上建立最小能量变分框架,从而得到描述裂纹发展的控制方程。不需要提前设定裂纹的形状、尺寸和方向,相场方法就能很好地描述裂纹的形成和扩展,为利用数值方法模拟裂纹扩展提供了一个严谨准确的理论框架。该文首次将相场方法用于模拟岩石裂隙扩展问题,预测包含不同岩桥倾角的预制双裂隙岩石类材料在单轴压缩作用下的损伤和破坏过程,并与室内试验结果进行对比。结果表明相场方法非常适合模拟岩石类材料内部复杂裂隙的萌生、扩展和连接过程,在岩体工程稳定性分析领域具有广阔的应用前景。

     

    Abstract: In the phase field method, by defining a continuous distribution function to approximate discontinuous cracks, a variational-based energy minimization framework was established to obtain the governing equations of the physical field. As an outstanding feature, it allows describing crack nucleation and branching without any prescription of the shape, size and orientation of the cracks, thus providing a very robust numerical framework for crack propagation simulation. In this paper, rock specimens containing two parallel cracks with different rock bridge angles are simulated under uniaxial compression condition to investigate crack nucleation and propagation configuration with the phase field method. The simulation results are compared with the experimental data, showing that the phase field method, as a new numerical technique in rock mechanics community, works quite satisfactorily in simulating the cracks nucleation and propagation of rock-like materials under the considered loading paths. Meanwhile, perspectives would be envisaged that the phase field method has important engineering significance in stability and durability analysis of rock structures.

     

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