Mechanics of Anisotropic Granular Materials

各向异性颗粒材料力学

• 批准号: RGPIN-2018-04573
• 负责人: Nadler, Ben
• 金额: $ 2.33万
• 依托单位: University of Victoria
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=760243
• 关键词: Mechanics; Anisotropic; Granular; Materials

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.

颗粒材料的力学具有多种应用，从谷物的有效运输和分类到山体滑坡和雪崩的建模。更好的理解，例如通过准确的模型，对于未来改进这些过程以及控制山体滑坡和雪崩是必要的。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、岩石或卵石，都由非球形（异形）颗粒组成。同样在工业中，大多数谷物都是非球形的，特别是在农作物具有拉长或扁平形状的农业和食品加工中，或者在药丸和药物胶囊的制药中。形状颗粒的微观结构和自我排列的能力提供了额外的程度复杂。异形晶粒的机械性能随晶粒微观结构排列的不同而显着变化，从而产生方向相关的机械性能（各向异性）。该研究计划将开发异形晶粒的数学模型，以增进我们对异形晶粒力学的基本理解。目前工程和物理界还没有很好地理解。开发的模型将与在 DynamiX：X 射线断层扫描以及澳大利亚悉尼大学粒子和谷物实验室进行的一系列实验进行比较。研究成形颗粒力学的文献中发表的著作很少，据我们所知，迄今为止尚未开发出任何数学模型。因此，所提出的研究计划将探索新颖、未被充分理解和研究很少的研究方向。该研究计划的主要新颖思想是使用各向异性本构定律明确地解释反映数学模型中晶粒排列的微观结构，以准确描述机械性能。主要的两个挑战是了解异形颗粒排列的机制以及机械性能与微观结构排列之间的关系。异形颗粒力学在农业（农作物）、食品加工中颗粒材料的运输、分选和储存方面有许多应用和制药（丸剂和药物胶囊）行业。该研究计划的结果将提供给这些行业，以改进其工艺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谷物加工行业产生重大影响。预计该研究项目还将对涉及非球形颗粒力学的其他系统的研究做出贡献，例如红细胞流动建模。