Dynamics in thin sheets in flow: flipping, folding, bending and buckling

在许多消费品和自然发生的系统的制造中，经常遇到涉及液体中悬浮颗粒的流动。了解悬浮颗粒的详细运动可以用来预测材料的性质和整体悬浮的行为。工程从业者可以使用这些信息来设计工艺，以实现从熟悉的家居用品到高度专业化的材料等产品的所需性能。该项目涉及数值计算，旨在理解在粘性液体中自由悬浮的柔性薄板的运动。当悬浮在流动中时，薄片（通常是最终材料的前体）可以表现出各种有趣的运动，所有这些都必须被理解，以便将薄片形成所需的形状。该项目将使用基于控制流体运动和薄板机械特性的基本方程的计算方法来分析薄板的运动和悬架的动力学。该项目将为不同学术水平的学生提供参与研究的机会。该项目将从威斯康辛大学的项目中招募学生，尤其是那些传统上在科学和工程领域代表性不足的学生。此外，调查人员将通过当地的男孩女孩俱乐部参与为K-12学生开发流体力学原理的实际演示。他们将招募和培训本科生和研究生作为年轻人的导师。用于分析流动中可变形颗粒的数值方法将适用于计算典型流动（如简单剪切流和拉伸流）中自由悬浮柔性板的动力学。薄板和薄板网的运动将与它们的静止形状和流动特性相关联。弯曲刚度的影响和可能形成的折痕将被研究和利用，以确定板材是否可以被流强迫形成结构，如简单的立方体。流动中双稳弹性结构的简单模型将被检验以量化薄片弹性和流动之间的相互作用。该项目的结果将提供有用的信息，以帮助分析作为薄片加工的电子和聚合物材料的制造。

CBET - 1604767PI: Graham, Michael D.Flows involving suspensions of particles in a liquid are frequently encountered in manufacturing of many consumer products and in naturally occurring systems. Understanding the detailed motion of the suspended particles can be used to predict the material properties and behavior of the suspension as a whole. This information can be used by engineering practitioners to design processes to achieve desired properties in products ranging from familiar household goods to highly specialized materials. This project involves numerical computations aimed at understanding the motion of thin flexible sheets that are freely suspended in a viscous liquid. When suspended in flow, the thin sheets, which are often the precursors of the final material, can exhibit a variety of interesting motions, all of which must be understood in order to form the sheets into desired shapes. The project will use computational methods based on fundamental equations that govern the motion of the fluid and the mechanical properties of the sheets to analyze the motion of the sheets and the dynamics of the suspension. The project will provide opportunities for students at various academic levels to participate in research. Students, especially those form groups traditionally underrepresented in science and engineering, will be recruited to the project from programs at the University of Wisconsin. In addition, the investigators will participate in developing hands-on demonstrations of fluid mechanics principles in action for K-12 students through local Boys and Girls Clubs. They will enlist and train undergraduate and graduate students to participate as mentors for the youngsters. Numerical methods that have been used to analyze deformable particles in flow will be adapted for calculating the dynamics of freely suspended flexible sheets in canonical flows such as simple shear and extensional flow. The motion of the sheets and networks of sheets will be correlated with their rest shapes and the characteristics of the flow. The effect of bending stiffness and the possible formation of creases will be investigated and exploited to determine whether the sheets can be forced by the flow into forming structures such as simple cubes. Simple models of bistable elastic structures in flow will be examined to quantify interactions between sheet elasticity and flow. The results of the project will provide useful information to help analyze fabrication of electronic and polymeric materials that are processed as thin sheets.