Relationships between structure, memory and flow in sheared disordered materials
Relationships between structure, memory and flow in sheared disordered materials
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DOI：
10.1038/s41567-022-01536-9
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发表时间：
2022-03-17
期刊：
影响因子：
19.6
通讯作者：
Arratia, P. E.
中科院分区：
文献类型：
--
作者：
Galloway, K. L.;Teich, E. G.;Arratia, P. E.
无序固体的一个基本挑战是从组成颗粒的微观排列预测宏观屈服——弹性行为转变为塑性行为的点。由于塑性重排的开始，产量伴随着能量耗散的突然大幅增加。这表明理解体流变学的一种途径是将颗粒构型映射到其变形模式。在这里，我们对二维致密胶体系统进行振荡剪切，测量颗粒轨迹和体流变学，并使用过量熵量化颗粒微观结构。我们的结果揭示了过量熵和能量耗散之间的直接关系，这种关系对粒子之间相互作用的性质不敏感。我们利用这种关系建立了一个将流变学与微观结构联系起来的物理模型。我们的研究结果提出了一个通过调整微观结构特性来调整无序材料的流变响应的框架。材料是否以及何时发生弹性或塑性变形取决于其微观结构。二维胶体系统的实验表明，在无序材料中，堆积密度、应力和与微观结构相关的熵控制着变形。
A fundamental challenge regarding disordered solids is predicting macroscopic yield-the point at which elastic behaviour changes to plastic behaviour-from the microscopic arrangements of constituent particles. Yield is accompanied by a sudden and large increase in energy dissipation due to the onset of plastic rearrangements. This suggests that one path to understanding bulk rheology is to map particle configurations to their mode of deformation. Here, we subject two-dimensional dense colloidal systems to oscillatory shear, measure the particle trajectories and bulk rheology, and quantify particle microstructure using excess entropy. Our results reveal a direct relation between excess entropy and energy dissipation that is insensitive to the nature of interactions amongst particles. We use this relation to build a physically informed model that connects rheology to microstructure. Our findings suggest a framework for tailoring the rheological response of disordered materials by tuning microstructural properties.Whether and when a material deforms elastically or plastically depends on its microstructure. Experiments on two-dimensional colloidal systems show that in disordered materials, packing density, stress and a microstructure-related entropy govern deformations.