Influence of cementation on the yield surface of rocks numerically determined from digital microstructures
Influence of cementation on the yield surface of rocks numerically determined from digital microstructures
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DOI：
10.1016/j.ijplas.2022.103338
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发表时间：
2022-05
影响因子：
9.8
通讯作者：
Martin Lesueur;M. Veveakis;H. Rattez
中科院分区：
文献类型：
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作者：
Martin Lesueur;M. Veveakis;H. Rattez
数字岩石物理学在表征取决于微观结构的主要性质（如孔隙度、渗透率或弹性模量）方面已达到成熟水平，方法是在岩石的μCT扫描图像上数值求解场方程。经过小变形或在深度，虽然，大多数岩石最终达到其弹性极限和互补的塑性特性需要描述完整的力学行为。目前，岩石的屈服面从其微观结构的确定往往是有限的极限分析或理想化的几何形状进行数值模拟得出的半解析标准。这种简化缺乏代表性，特别是对于直接影响孔隙-颗粒界面的过程，如在成岩作用期间发生的胶结现象。最终，只有在数字化微观结构上进行的弹塑性直接数值模拟才能用于评估不同胶结材料的强度及其随微观结构变化的演变。在这项研究中，我们提供了一个全面的参数研究的影响，胶结对岩石强度的真实的微观结构的胶结颗粒材料。与大多数以前的研究相比，整个屈服面的数值确定（使用有限元法），以评估不同的应力路径胶结的影响。证实了先前已知的岩石随着胶结体积的增加而增强的趋势。探讨了水泥的弹性模量、摩擦力和粘聚力对岩石屈服面影响的新结果。所获得的信封进行比较，通过实验数据和现有的模型。在这项研究中提出的框架展示了更广泛的可能性，确定任何岩石或多孔材料的屈服面从其微观结构。
Digital Rock Physics has reached a level of maturity on the characterisation of primary properties that depend on the microstructure – such as porosity, permeability or elastic moduli – by numerically solving field equations on μCT scan images of rock. After small deformations or at depth though, most rocks eventually reach their limit of elasticity and the complementary plastic properties are needed to describe the full mechanical behaviour. Currently, determination of a rock’s yield surface from its microstructure is often restricted to semi-analytical criteria derived by limit analysis or numerical simulations performed on idealised geometries. Such simplification lacks representativeness, particularly for processes that affect directly the pore-grain interface such as the cementation phenomenon, happening during diagenesis. Eventually, only direct numerical simulation of elasto-plasticity performed on digitalised microstructures can be used to assess the strength of different cemented materials and its evolution with the alteration of the microstructure. In this study, we provide a comprehensive parametric study on the impact of cementation on rock strength for real microstructures of cemented granular materials. Compared to most previous studies, the whole yield surface is determined numerically (using Finite Element Method) in order to assess the influence of cementation for different stress-paths. The previously known tendency of rock to strengthen with increasing cementation volume is verified. New results on the influence of cement property namely Young’s modulus, friction and cohesion on the rock’s yield surface are explored. The envelopes obtained are compared to the ones obtained by experimental data and existing models. The framework presented in this study showcases the wider possibility of determining any rock’s or porous material’s yield surface from its microstructure.