发表机构
Kajima Technical Research Institute (KATRI); Tokyo University of Marine Science and Technology; University of Tsukuba; Gonville & Caius College, University of Cambridge（鹿岛技术研究所; 东京海洋大学; 筑波大学; 剑桥大学贡维尔与凯斯学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过数值模拟揭示硬-软颗粒混合物中胞元统计的自组织规律，发现其具有准普适性，并可用统一模型描述。
AI 中文摘要
颗粒系统的自组织是其宏观行为的关键决定因素，并已在硬颗粒组装中被广泛研究。我们使用数值模拟来测试这一理解在硬颗粒和软颗粒混合物中的适用性，重点关注接触网络中最小的不可约环——胞元，作为结构描述符。我们表明，尽管在等向压实下胞元统计显示出稳健的定性特征，但它们依赖于颗粒间摩擦系数 $\mu$ 和软颗粒占比 $\kappa$。具体而言：(i) 四元体面积分布保持 $\Gamma$ 形式，但其参数随 $\mu$ 和 $\kappa$ 系统性地变化。(ii) 在不考虑力学稳定性的情况下，通过最大化熵对胞元有序分布（COD）的预测在大胞元阶数下变得越来越不准确。(iii) 无论 $\mu$ 如何，归一化的胞元应力分布都塌缩到一个主 Weibull 形式上，其唯一的形状参数仅弱依赖于 $\kappa$。这表明存在一种准普适形式，在软颗粒占比极高时可能略有退化。(iv) 胞元优先沿局部最大主应力方向排列，表现出与硬颗粒中相同的应力-结构协同自组织。胞元统计对软颗粒添加的相对稳健性表明，硬颗粒和硬-软颗粒混合物可以用同一模型描述。
英文摘要
Self-organisation of granular systems is a key determinant of their macroscopic behaviour and has been studied extensively in assemblies of hard particles. We use numerical simulations to test this understanding in mixtures of hard and soft particles, focusing on cells, the smallest irreducible loops of the contact network, as structural descriptors. We show that, while the cell statistics display robust qualitative features under isotropic compaction, they depend on inter-particle friction, $μ$, and soft-particle fraction, $κ$. Specifically, (i) the quadron area distributions retain a $Γ$ form, albeit with parameters that vary systematically with $μ$ and $κ$. (ii) Predictions of the cell order distribution (COD) by maximising the entropy, without taking mechanical stability into consideration, become increasingly inaccurate at large cell orders. (iii) Irrespective of $μ$, the normalised cell stress distributions collapse onto one master Weibull form, whose only shape parameter depends weakly on $κ$. This suggests a quasi-universal form that may deteriorate slightly at very high fractions of soft particles. (iv) Cells align preferentially along the local major principal stress direction, showing the same coordinated stress--structure self-organisation as in hard particles. The relative robustness of cell statistics to the addition of soft particles suggests that hard and hard--soft granular mixtures can be described by one model.
Comments11 pages, 18 figures
