Statistical and Dynamical Properties of Spherical and Non-Spherical Granular Materials

非技术摘要：将用高速成像技术进行实验，以了解颗粒形状和磁化对颗粒物质特性的影响。这些研究很重要，因为颗粒材料是工业过程(如粮仓、化肥)和自然现象(如泥石流)中普遍存在的成分，但目前还没有基本理论来描述它们。我们建议在广泛的参数范围内测试和发展颗粒物质的数学模型。此外，颗粒的形状多种多样，将其影响纳入描述不同种类颗粒如何组织和流动的模型中是很重要的。拟议的工作将对研究生培养产生重大影响。这笔助学金将增强本科生在实验室的研究经验，这项研究还将被改编成一门现代力学课程。当地社区将通过专题研讨会和研究人员在附近的高中发表演讲来接触到这项研究，以激发人们对科学的兴趣。技术摘要：利用高速成像技术研究球形和非球形振动流态化颗粒材料的统计和动力学特性。颗粒形状的影响将是主要的焦点，将使用振动棒、二聚体和由连接的珠链组成的聚合物来研究。我们将探讨耗散和各向异性相互作用对新结构自组装和全球动力学的影响。在热系统中，在扁平粒子中观察到长程有序导致向列态和近晶态，这据说可以简化分析。颗粒物质中的颗粒间摩擦是否像这些方法所假设的那样抑制了对相空间的统一探索，这是一个悬而未决的问题。还将研究磁化强度和长程相互作用对自组装的影响，并与为铁磁流体建立的偶极硬球模型进行比较。平衡统计物理和熵的考虑在多大程度上适用于耗散颗粒系统将被研究。在寻找纳米粒子自组装的有效策略的背景下，这样的实验也很有趣。除了发展工业中需要更有效处理的材料的基础知识外，拟议的工作还将直接支持研究生的培训，增强本科生的研究经验，影响现代力学课程的发展，并通过讲座让学生进入邻近的高中，从而影响当地社区。

Non-technical abstract: Experiments with high-speed imaging techniques will be conducted to understand the impact of particle shape and magnetization on the properties of granular matter. These studies are important because granular materials are ubiquitous constituents in industrial processes (e.g., food grain silos, fertilizers) and natural phenomena (e.g., mudslides), and yet no fundamental theory is currently available to describe them. We propose to test and develop mathematical model for granular matter over a wide range of parameters. Furthermore, grains come in all shapes and it is important to incorporate its impact into models that describe how different kinds of grains organize and flow. The proposed work will have significant impact on graduate student training. The grant will enhance research experience of undergraduate students in the laboratory, and the research will be also adapted into a modern course on mechanics. Local community will be exposed to the research via topical workshops, and by the researchers speaking at neighboring high schools to excite interests in the sciences. Technical abstract: The statistical and dynamical properties of spherical and non-spherical vibro-fluidized granular materials will be investigated with high-speed imaging techniques. The impact of particle shape will be the main focus and will be studied using vibrated rods, dimers, and polymers composed of linked bead chains. The impact of dissipation and anisotropic interactions on the self-assembly of novel structures and global dynamics will be probed. In thermal systems, long-range order is observed in oblate particles leading to nematic and smectic states which is said to simplify analysis. Whether interparticle friction in granular matter suppresses uniform exploration of phase space, as assumed by such approaches, is an open question. The effect of magnetization and long-range interaction on the self-assembly will be also studied, and compared with the dipolar hard sphere model developed for ferro-fluids. The extent to which equilibrium statistical physics and entropic considerations apply to dissipative granular systems will be investigated. Such experiments are interesting in the context of finding effective strategies for self-assembly in nano-particles as well. Besides developing fundamental knowledge on materials which need to be handled more efficiently in industry, the proposed work will directly support training of graduate students, enhance research experience of undergraduate students, impact development of a modern mechanics course, and impact the local community by engaging students in neighboring high schools via lectures.