A phase‐field approach for compaction band formation due to grain crushing
A phase‐field approach for compaction band formation due to grain crushing
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DOI：
10.1002/nag.3436
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发表时间：
2022-08
影响因子：
4
通讯作者：
S. C. Ip;R. Borja
中科院分区：
文献类型：
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作者：
S. C. Ip;R. Borja
压实带是局部压缩变形的板状区域，几乎没有或没有剪切偏移。通常在高孔隙度岩石中观察到，它们可以根据其模式和相对于最大主应力的方向分为几个亚型。材料性质和加载条件对压实带类型的综合影响尚未完全了解，对其形成的现实模拟并不总是成功的。在这项研究中，提出了一种用于捕获压实带的形成和传播的相场方法。在经典相场公式中使用的断裂能被解释为由颗粒破碎驱动，并且在本文中由断裂力学理论表征。本文提出了一种新的自由能函数分解，其中塑性压缩流储存的能量驱动颗粒破碎。根据能量释放率的值，该模型预测不同风格的压实带，显着一致，在现场观察到的。数值模拟表明，围压，塑性和临界破裂能量的预测压实带的风格的作用。
Compaction bands are tabular regions of localized compressive deformation with little or no shear offset. Often observed in high‐porosity rocks, they can be classified into several subtypes based on their pattern and orientation with respect to the maximum principal stress. The combined effects of material properties and loading conditions on the type of compaction bands that develop are not fully understood, and realistic simulations of their formation are not always successful. In this study, a phase‐field approach for capturing the formation and propagation of compaction bands is proposed. The fracture energy utilized in classic phase‐field formulations is interpreted to be driven by grain crushing and is herein characterized by breakage mechanics theory. A new decomposition of the free energy function is introduced in which the energy stored by plastic compactive flow drives grain crushing. Depending on the value of the energy release rate, the model predicts different styles of compaction bands that are remarkably consistent with those observed in the field. Numerical simulations demonstrate the role of confining pressure, plasticity, and critical breakage energy on the styles of the predicted compaction bands.