Abstract The microscopic characteristics greatly influence the nonlinear mechanical behavior and failure process of rock materials. In the present work, the experimental investigations are firstly performed including microstructural observations and macroscopic laboratory tests. Based on various experimental evidences, a micromechanical damage model is proposed according to the microscopic characteristics for the description of the local mechanical features such as mineralogical composition, plastic deformation and failure process caused by induced damage. The microstructure of the studied rocks is artificially reconstructed using Fast Fourier Transforms (FFT) based technique without meshing the complex geometry composed of clay matrix and two randomly distributed mineral inclusions. Comparisons between experimental data and numerical predictions are presented for uniaxial and triaxial compression tests. The characterization of damage evolution is visualized by the direct full field numerical simulations corresponding the macroscopic mechanical response. The effects of induced damage, the confining pressure and the overburden depth on the nonlinear mechanical behavior and failure process are schematically studied.

中文翻译：

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微结构对脆性岩石力学行为和破坏过程影响的实验和数值研究

摘要 微观特征极大地影响岩石材料的非线性力学行为和破坏过程。在目前的工作中，首先进行实验研究，包括微观结构观察和宏观实验室测试。基于各种实验证据，根据微观特征提出了一种微观力学损伤模型，用于描述由诱导损伤引起的矿物成分、塑性变形和破坏过程等局部力学特征。所研究岩石的微观结构是使用基于快速傅立叶变换 (FFT) 的技术人工重建的，无需对由粘土基质和两个随机分布的矿物包裹体组成的复杂几何形状进行网格划分。对单轴和三轴压缩试验的实验数据和数值预测进行了比较。损伤演化的表征通过与宏观力学响应相对应的直接全场数值模拟来可视化。示意性地研究了诱导损伤、围压和覆盖层深度对非线性力学行为和失效过程的影响。