Shear-Jammed, Fragile, and Steady States in Homogeneously Strained Granular Materials
Shear-Jammed, Fragile, and Steady States in Homogeneously Strained Granular Materials
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均质应变颗粒材料中的剪切堵塞、脆性和稳态
DOI：
10.1103/physrevlett.123.158001
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发表时间：
2019
影响因子：
8.6
通讯作者：
Behringer Robert P
中科院分区：
文献类型：
--
作者：
Zhao Yiqiu;Bares Jonathan;Zheng Hu;Socolar Joshua E S;Behringer Robert P
利用一种新型的多环底库埃特剪切装置研究了颗粒材料剪切时的堵塞相图。该装置使用小的基础摩擦力施加体积守恒的线性剪切，没有剪切带的颗粒系统组成的摩擦光弹性盘。由于其圆形几何形状，该装置可以产生任意大的剪切应变，并且剪切方向可以反转，使我们能够测量区分剪切堵塞和脆弱状态的特征。我们报告系统测量的应力，应变和接触网络结构的相边界，已经很难通过传统的实验技术，包括屈服应力曲线和堵塞曲线接近，最小的包装分数支持剪切堵塞状态。我们观察到的脆性状态下产生的大剪切应变范围内。我们还发现了一个过渡的准静态定常流的特点为中心周围的收益率曲线作为一个功能的包装分数。近段时间，平均接触数、组构各向异性和非振子分数均表现出斜率的变化。然而，稳定流显示出可测量的偏离基线线性剪切剖面，并且在剪切带中局部化流动。
We study the jamming phase diagram of sheared granular material using a novel Couette shear setup with a multiring bottom. The setup uses small basal friction forces to apply a volume-conserving linear shear with no shear band to a granular system composed of frictional photoelastic discs. The setup can generate arbitrarily large shear strain due to its circular geometry, and the shear direction can be reversed, allowing us to measure a feature that distinguishes shear-jammed from fragile states. We report systematic measurements of the stress, strain, and contact network structure at phase boundaries that have been difficult to access by traditional experimental techniques, including the yield stress curve and the jamming curve close to, the smallest packing fraction supporting a shear-jammed state. We observe fragile states created under large shear strain over a range of. We also find a transition in the character of the quasistatic steady flow centered aroundon the yield curve as a function of packing fraction. Near, the average contact number, fabric anisotropy, and nonrattler fraction all show a change of slope. Abovethe steady flow shows measurable deviations from the basal linear shear profile, and abovethe flow is localized in a shear band.