Fracturing in Wet Granular Media Illuminated by Photoporomechanics
Fracturing in Wet Granular Media Illuminated by Photoporomechanics
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光孔隙力学照明的湿颗粒介质中的破裂
DOI：
10.1103/physrevapplied.18.064081
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发表时间：
2022
影响因子：
4.6
通讯作者：
Juanes, Ruben
中科院分区：
文献类型：
--
作者：
Meng, Yue;Li, Wei;Juanes, Ruben
我们研究了颗粒介质的流体诱导变形和破裂，并应用微结构力学来揭示支撑的颗粒尺度力学。我们制造的球形光弹性颗粒的直径为2毫米，形成一个单层的颗粒包在一个圆形的Hele-Shaw细胞，最初充满了粘性流体。我们的系统的关键显著特征是，与球形颗粒，颗粒包具有连接的孔隙空间，从而允许孔隙压力扩散和耦合poromechanical过程中的有效应力的研究。我们将空气注入充满流体的光弹性颗粒充填体中，改变初始充填密度和围压。利用我们最近开发的实验技术，光弹性力学，我们发现了两种不同的流体侵入模式：在充满流体的弹性介质中的破裂（具有较强的光弹性响应）和摩擦流体中的粘性指进（具有较弱或可忽略的光弹性响应）。我们直接可视化的有效应力场的发展，并发现一个有效的应力阴影背后的传播裂缝尖端，颗粒包表现出不排水的行为。我们概念化的系统的行为，通过一个机制模型的楔形颗粒包有界的两个不断增长的裂缝。该模型捕捉孔隙压力建立的应力阴影区域内和颗粒压实的环形区域外。我们的模型表明，堵塞过渡决定了不同的流变行为的湿颗粒包，从摩擦为主的弹性为主的响应。
We study fluid-induced deformation and fracture of granular media and apply photoporomechanics to uncover the underpinning grain-scale mechanics. We fabricate spherical photoelastic particles of 2-mm diameter to form a monolayer granular pack in a circular Hele-Shaw cell that is initially filled with a viscous fluid. The key distinct feature of our system is that, with spherical particles, the granular pack has a connected pore space, thus allowing for pore-pressure diffusion and the study of effective stress in coupled poromechanical processes. We inject air into the fluid-filled photoelastic granular pack, varying the initial packing density and confining weight. With our recently developed experimental technique, photoporomechanics, we find two different modes of fluid invasion: fracturing in fluid-filled elastic media (with strong photoelastic response) and viscous fingering in frictional fluids (with weak or negligible photoelastic response). We directly visualize the evolving effective stress field and discover an effective stress shadow behind the propagating fracture tips, where the granular pack exhibits undrained behavior. We conceptualize the behavior of the system by means of a mechanistic model for a wedge of the granular pack bounded by two growing fractures. The model captures the pore-pressure build-up inside the stress shadow region and the grain compaction in the annular region outside. Our model reveals that a jamming transition determines the distinct rheological behavior of the wet granular pack, from a friction-dominated to an elasticity-dominated response.
影响因子：
1.6
作者：
Mikelic, Andro;Wheeler, Mary F.;Wick, Thomas
通讯作者：
Wick, Thomas
影响因子：
2.4
作者：
D. Wendell;K. Luginbuhl;J. Guerrero;Anette Hosoi
通讯作者：
Anette Hosoi