非球体随机填充结构的宏观和微观特性研究

Random packing structures are very common in nature and industry, they also have close relations with the structure of liquid. However, due to the complexity of simulation and experiment, we know very few about the random packing structure of non-spherical particles. Existing theories and models all have their limitations. The project develops the state theory of Maximal Random Close Packing (MRCP), including the verification of existence, uniqueness and conditions. The MRCP packing density of cubes is measured as well. The influences of axis ratios, surface shape, symmetry, eccentricity and concavity on the random packing density are investigated. A linear superposition model is built for predicting the random packing density of particles with any shape. The macro-micro and physical-mechanical properties of MRCP structure are studied, and are compared with that of MRJ state. Packing experimental techniques are also developed, including the X-ray microtomography and rebuilding of 3D digital models. The results of the project will give promotions to a number of scientific and industrial fields.

随机填充结构不但在自然界和工业领域十分常见，而且与液态物质结构有密切关系。然而由于实验和计算的复杂性，目前对于非球形颗粒随机填充结构的了解十分有限，现有的几种理论和模型均存在缺陷。本项目将建立最大随机密填充(MRCP)状态理论，验证MRCP状态的存在性、唯一性和生成条件，测定立方体MRCP随机填充率；研究三轴比、表面形状、对称、偏心、非凸等因素对随机填充率的影响，建立任意形状颗粒随机填充率预测的线性叠加模型；研究MRCP随机填充结构的宏观和微观、物理和力学特征，并比较与MRJ等状态的异同；研究相关填充实验技术，建立一套完整的X射线断层扫描及三维重建技术实验平台。本项目的研究成果将会对多个学科和工业领域产生积极的促进作用。

非球体随机填充在自然界、工业生产和日常生活中十分常见，也与液态物质结构密切相关。本项目提出了最密随机填充的概念，提出了约束填充算法生成最密随机填充，获得了常见非球形状颗粒的最密随机填充，其中立方体最密随机填充率约为0.637。最密随机填充状态为颗粒随机填充的研究提供了一种统一的平台。研究了颗粒形状变化，包括长细比、表面形状、圆角度、弯曲等对填充性质的影响，发现长细比在0.7和1.5的填充率双峰特性是颗粒轴比对填充率影响的普遍规律，小圆角四面体的填充可以比理想四面体更密。研究了随机填充结构的物理和力学特性，发现四面体局部簇结构，并用簇的相对数量作为四面体局部序参数，得到了四面体最随机阻塞填充。建立了颗粒三维建模、3D打印、填充分析和力学实验等实验手段和环境。该项目的研究成果进一步丰富和加深了对非球体随机填充的认识，也将对多个学科和工业领域产生积极的促进作用。