探究不连续剪切增稠的本质：超越平均场描述
Investigating the Nature of Discontinuous Shear Thickening: Beyond a Mean-Field Description
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中文总结 AI 辅助
本研究利用高阶聚类分析工具研究致密悬浮液模拟中的力网络，在力空间构建有效相互作用势，揭示接近不连续剪切增稠时该势能随密度和应力发生显著变化，为超越平均场描述的涌现场理论提供微观依据。
中文摘要 AI 辅助
致密悬浮液在剪切应力达到临界值时，其粘度会发生剧烈增加。这一现象被称为不连续剪切增稠（DST），已被归因于随着剪切应力增加，颗粒相互作用中变为摩擦接触的比例增大；并且已有成功的平均场理论被发展出来，用以解释伴随的各种流变学性质。然而，在微观尺度上，传统的结构分析测量手段，如颗粒位置对关联函数，在DST开始时并未显示出显著变化，尽管近期工作表明，在接触力的对偶空间中进行类似分析确实会在该转变处导致显著变化。此外，实验结果已提示存在更高阶的微观关联，以及将偏离平均场描述的涨落纳入考虑的重要性。为此，我们使用一种高阶聚类分析工具，研究从致密悬浮液模拟中获得的力网络，以在力空间中构建一个有效的相互作用势。我们表明，在接近DST时，该势能随密度和应力发生显著变化。我们讨论了这些观测结果对DST转变的涌现场理论的意义。
英文摘要
Dense suspensions can undergo a dramatic increase in viscosity at a critical value of the shear stress. This phenomenon, termed discontinuous shear thickening (DST), has been attributed to an increase in the fraction of particle interactions becoming frictional with increasing shear stress, and a successful mean-field theory has been developed to explain various accompanying rheological properties. On a microscopic scale, however, conventional structural analysis measures such as the grain-position pair correlation function show no significant changes with the onset of DST, though recent work has shown that similar analysis in the dual space of contact forces does lead to marked changes at this transition. Furthermore, experimental results have suggested the existence of higher-order microscopic correlations and the importance of incorporating fluctuations away from a mean-field description. To this end, we use a higher-order cluster analysis tool to study the force networks obtained from simulations of dense suspensions to construct an effective interaction potential in force space. We show that there are significant changes occurring in this potential as a function of density and stress close to DST. We discuss the implications of these observations on an emergent field theory of the DST transition.
发表机构
- Brandeis University（布兰迪斯大学）
- Georgetown University（乔治城大学）
- CUNY City College of New York（纽约市立学院）
- University of Chicago（芝加哥大学）
机构由 AI 辅助整理，请以论文原文为准。
