论文标题
应力压力相关性揭示了凝胶中的力链
Stress-stress Correlations Reveal Force Chains in Gels
论文作者
论文摘要
我们使用2D和3D数值模拟研究了软颗粒凝胶中显微胁迫的空间相关性。我们使用了一个最近开发的理论框架，可预测在外部载荷下获得刚性的无定形组件中应力压力相关性的分析形式。这些相关性在傅立叶空间中表现出捏合点的奇异性，导致远距离相关性和在真实空间中的强烈各向异性，这是粒状固体中力链的起源。我们对低颗粒体积分数的模型颗粒凝胶的分析表明，这些软材料中的应力应力相关性具有与颗粒固体中的特性非常相似，并且可用于识别力链。我们表明，由于固化过程中刚性结构的出现，应力压力相关性可以将软盘与刚性凝胶网络区分开，而强度模式反映了剪切模量和网络拓扑的变化。
We investigate the spatial correlations of microscopic stresses in soft particulate gels, using 2D and 3D numerical simulations. We use a recently developed theoretical framework predicting the analytical form of stress-stress correlations in amorphous assemblies of athermal grains that acquire rigidity under an external load. These correlations exhibit a pinch-point singularity in Fourier space leading to long-range correlations and strong anisotropy in real space, which are at the origin of force-chains in granular solids. Our analysis for the model particulate gels at low particle volume fractions demonstrates that stress-stress correlations in these soft materials have characteristics very similar to those in granular solids and can be used to identify force chains. We show that the stress-stress correlations can distinguish floppy from rigid gel networks and the intensity patterns reflect changes in shear moduli and network topology, due to the emergence of rigid structures during solidification.
