论文标题
流动诱导的刚性渗透剪切悬浮液中的刚性渗透
Flow induced rigidity percolation in shear thickening suspensions
论文作者
论文摘要
不连续的剪切增厚（DST）与悬浮液的粘度急剧上升，施加剪切速率的提高。在最近的研究中强调的DST的一个关键特征是随着悬浮液的增长，测得的应力的波动非常大。微观结构发展与压力波动的急剧增加之间的明显联系尚未建立。为了确定这种行为的微观结构基础，我们进行了剪切致密悬浮液的模拟。通过分析粒子接触网络，我们确定了约束颗粒的子集，这些粒子直接导致粘度快速上升和较大的应力波动。实际上，这两种现象都可以通过约束粒子网络的生长和渗透来解释，这与刚性渗透直接类似。有限尺寸的缩放分析证实这是一种渗滤现象，使我们能够估计关键指数。我们的发现揭示了基于DST的特定微观结构过渡。
Discontinuous shear thickening (DST) is associated with a sharp rise of a suspension's viscosity with increasing applied shear rate. A key signature of DST, highlighted in recent studies, is the very large fluctuations of the measured stress as the suspension thickens. A clear link between microstructural development and the dramatic increase of the stress fluctuations has not been established yet. To identify the microstructural underpinnings of this behavior, we perform simulations of sheared dense suspensions. By analyzing particle contact networks, we identify a subset of constrained particles that contribute directly to the rapid rise in viscosity and the large stress fluctuations. Indeed, both phenomena can be explained by the growth and percolation of constrained particle networks -- in direct analogy to rigidity percolation. A finite size scaling analysis confirms this is a percolation phenomenon and allows us to estimate the critical exponents. Our findings reveal the specific microstructural transition that underlies DST.
