Dynamic crack branching in unsaturated porous media holds significant relevance in various fields, including geotechnical engineering, geosciences, and petroleum engineering. This article presents a numerical investigation into dynamic crack branching in unsaturated porous media using a recently developed coupled micro‐periporomechanics (PPM) paradigm. This paradigm extends the PPM model by incorporating the micro‐rotation of the solid skeleton. Within this framework, each material point is equipped with three degrees of freedom: displacement, micro‐rotation, and fluid pressure. Consistent with the Cosserat continuum theory, a length scale associated with the micro‐rotation of material points is inherently integrated into the model. This study encompasses several key aspects: (1) Validation of the coupled micro‐PPM paradigm for effectively modeling crack branching in deformable porous media, (2) Examination of the transition from a single branch to multiple branches in porous media under drained conditions, (3) Simulation of single crack branching in unsaturated porous media under dynamic loading conditions, and (4) Investigation of multiple crack branching in unsaturated porous media under dynamic loading conditions. The numerical results obtained in this study are systematically analyzed to elucidate the factors that influence crack branching in porous media subjected to dynamic loading. Furthermore, the comprehensive numerical findings underscore the efficacy and robustness of the coupled micro‐PPM paradigm in accurately modeling dynamic crack branching in variably saturated porous media.

中文翻译：

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通过多相微周孔隙力学模拟不饱和多孔介质中的动态裂纹分支

不饱和多孔介质中的动态裂纹分支在岩土工程、地球科学和石油工程等各个领域都具有重要意义。本文使用最近开发的耦合微周孔隙力学 (PPM) 范式对不饱和多孔介质中的动态裂纹分支进行了数值研究。该范例通过结合固体骨架的微旋转来扩展 PPM 模型。在这个框架内，每个质点都配备了三个自由度：位移、微旋转和流体压力。与 Cosserat 连续统理论一致，与质点微旋转相关的长度尺度本质上集成到模型中。这项研究涵盖了几个关键方面：(1) 验证耦合微 PPM 范式，以有效模拟可变形多孔介质中的裂纹分支，(2) 检查排水条件下多孔介质中从单分支到多分支的转变，( 3）动载条件下非饱和多孔介质单裂纹分支的模拟，以及（4）动载条件下非饱和多孔介质多裂纹分支的研究。对本研究中获得的数值结果进行了系统分析，以阐明影响动态载荷下多孔介质中裂纹分支的因素。此外，综合数值研究结果强调了耦合微 PPM 范式在精确模拟可变饱和多孔介质动态裂纹分支方面的有效性和鲁棒性。