Mechanics of Anisotropic Granular Materials

颗粒材料的力学有多种应用，从颗粒的有效运输和分选到滑坡和雪崩的建模。更好的了解，例如通过精确的模型，对于未来改进这些过程和控制滑坡和雪崩是必要的。晶粒表现出非常复杂的力学响应，可以从静态状态过渡到动态流动状态。所有自然形成的颗粒，包括沙子、岩石或鹅卵石，都是由非球形颗粒组成的。同样在工业中，大多数谷物都是非球形的，特别是在农业和食品加工中，作物的形状呈细长或扁平状，或者在制药中，药丸和药物胶囊。***晶粒的微观结构和排列能力增加了复杂性。异型晶粒的力学性能随晶粒的微观组织排列而显著变化，从而产生方向相关的力学性能（各向异性）。***该研究项目将开发异形颗粒的数学模型，以促进我们对异形颗粒力学的基本理解，这是目前工程和物理学界尚未很好地理解的。开发的模型将与DynamiX x射线断层扫描和澳大利亚悉尼大学粒子和颗粒实验室进行的一系列实验进行比较。研究形粒力学的文献很少，据我们所知，到目前为止还没有建立数学模型。因此，提出的研究计划将探索新颖，不太了解和很少研究的研究方向。***本研究的主要新颖思想是利用各向异性本构律在数学模型中明确地解释反映晶粒取向的微观组织，从而准确地描述力学性能。主要的两个挑战是了解晶粒形取向的机制以及力学性能与微观组织排列之间的关系。异形颗粒的力学在农业（作物）、食品加工和制药（药丸和药物胶囊）工业中颗粒物料的运输、分选和储存方面有许多应用。这项研究计划的结果将提供给这些行业，以改善他们的工艺，以及工业设计和制造配套机械。预计这些见解和开发的数学模型将对科学和许多加工粮食的行业产生重大影响。预计该研究项目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.