Mechanics of Anisotropic Granular Materials

颗粒材料的力学有着广泛的应用，从谷物的有效运输和分类到滑坡和雪崩的建模。更好的理解，例如通过精确的模型，是必要的，为未来改进这些过程和控制滑坡和雪崩。颗粒表现出非常复杂的机械响应，可以从静态转变为动态流动。所有天然存在的颗粒，包括沙子、岩石或鹅卵石，都是由非球形颗粒组成的。此外，在工业中，大多数谷物是非球形的，特别是在农业和食品加工中，作物具有细长或扁平的形状，或者在制药中具有药丸和药物胶囊。微结构和成形颗粒自身排列的能力提供了额外的复杂度。成型晶粒的机械性能随着晶粒的微观结构排列而显著变化，这导致方向相关的机械性能（各向异性）。该研究计划将开发成型颗粒的数学模型，以促进我们对成型颗粒力学的基本理解，这是目前工程和物理界还没有很好地理解的。开发的模型将与澳大利亚悉尼大学DynamiX：X射线断层扫描和粒子和颗粒实验室进行的一系列实验进行比较。很少有工作发表在文献中研究力学的成型颗粒，据我们所知，没有数学模型已开发的。因此，拟议的研究计划将探索新的，不太了解和很少研究的研究方向。在这项研究计划中的主要新颖的想法是明确占的微观结构，反映晶粒排列的数学模型，使用各向异性本构关系，以准确地描述力学性能。主要的两个挑战是理解成形晶粒排列的机制以及机械性能与微观结构排列之间的关系。颗粒力学在农业（农作物）、食品加工和制药（药丸和药物胶囊）工业中的颗粒材料的运输、分选和储存中有许多应用。这项研究计划的结果将提供给这些行业，以改善他们的过程以及行业设计和制造支持机械。预计这些见解和开发的数学模型将对科学和许多粮食加工行业产生重大影响。预计该研究计划还将对涉及非球形颗粒力学的其他系统的研究做出贡献，例如模拟红细胞流动。

The mechanics of granular materials has diverse applications ranging from the efficient transportation and sorting of grains to the modeling of landslides and avalanches. Better understanding, e.g. through accurate models, is necessary for future improvements of these processes and the control of landslides and avalanches. Grains show a very complex mechanical response that can transition from a static-state into a dynamic flow.***All naturally occurring grains, including sand, rocks or pebbles, consist of non-spherical (shaped) grains. Also in industry, most grains are non-spherical, in particular in agriculture and food processing where crops have elongated or flattened shapes, or in pharmaceutics with pills and drug capsules.***The microstructure and ability of shaped grains to align themselves provides an added degree of complexity. The mechanical properties of shaped grains vary significantly with the microstructure alignment of the grains which gives rise to direction dependent mechanical properties (anisotropy).***This research program will develop mathematical models for shaped grains to advance our fundamental understanding of the mechanics of shaped grains which is currently not well understood by the Engineering and Physics communities. The developed models will be compared with a range of experiments conducted at the DynamiX: X-ray tomography and the Particles and Grains Laboratories at the University of Sydney, Australia.***Very little work is published in the literature studying the mechanics of shaped grains and, to our knowledge, no mathematical model has been developed as of yet. Hence, the proposed research program will explore research directions which are novel, not well understood and very little studied.***The main novel idea in this research program is to explicitly account for the microstructure reflecting the grain alignment in the mathematical models using anisotropic constitutive laws to accurately describe the mechanical properties. The main two challenges are to understand the mechanism of shaped grains alignment and the relationship between the mechanical properties and the microstructure arrangement.***The mechanics of shaped grains has many applications in transportation, sorting and storing of granular materials in agriculture (crops), food processing and the pharmaceutics (pills and drug capsules) industries. The results of this research program will be made available to these industries to improve their process as well as industries designing and manufacturing supporting machinery. It is anticipated that the insights and the developed mathematical models will have substantial impact both scientifically and on the many industries processing grain. It is also anticipated that this research program will have contribution to research on other systems involving the mechanics of non-spherical particles such as modeling red blood cells flow.