Tunable Tensegrity Structures and Metamaterials

张拉格栅是一种特殊的结构，它由受压支柱组成，由处于预应力状态的连续张拉索网络连接。这些结构表现出极端的性能，如低质量和重量，高弹性，高强度和丰富的可调性。这些特性可用于工程应用，并有可能超过目前已建立的解决方案的性能。此外，张拉整体结构已被用于越来越多的工程应用中，包括可展开的圆顶，可调谐天线和可持续的自适应太阳能电池阵列，仅举几例。从几何角度来看，张拉网格已被证明是可扩展的：从大型空间结构到微米和纳米尺度的应用已经证明了其跨尺度的适用性。虽然许多人认为预应力要求是张拉整体结构进一步发展的障碍，但本项目通过继续研究预应力要求使张拉整体结构能够展开、可调和变形的前提，探索了这一新兴趋势。该研究项目将有助于理论，计算和实验能力，以推进张拉整体结构和超材料领域，并发现张拉整体功能的新模式。该研究将通过建立一个灵活的教育和推广计划来补充，该计划基于课程开发，培训演示，并通过传播我们的研究结果和工具来提高对这些结构的认识，此外还将向公众和研究社区广泛分享调查员的经验。该研究的目标是实现对张拉整体结构的深入理解，以便：（i）设计或找到任何几何形状的张拉整体结构，可能有孔和开口，允许应用特定的张拉整体结构设计;（ii）使用增材制造进行快速原型制作和新设计的概念验证;（iii）建造及制造大型应用型张拉整体结构（例如，人类规模），记录经验，传播挑战和解决办法;（iv）设计可编程/可重编程的张拉整体超材料，并使用Bloch波分析框架研究其动态特性;以及（v）研究预应力水平对改变张拉整体超材料内带隙尺寸和分布的影响。具体而言，该项目应导致优雅的Class-1（“浮动支柱”）可编程张拉整体超材料的创建和分析，以及可用于临时住所或结构部件保护设计的大型张拉整体结构等。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Tensegrities are special structures composed of compression struts connected by a continuous network of tension cables in a state of prestress. These structures exhibit extreme properties such as low-mass and weight, high-resilience, high-strength, and rich-tunability. These properties can be harnessed for use in engineering applications and potentially exceed the performance of currently established solutions. In addition, tensegrity structures have been used in an increasing number of engineering applications, including deployable domes, tunable antennas, and sustainable adaptive solar arrays to name a few. From a geometrical perspective, tensegrities have been shown to be scalable: applications ranging from large space structures to the micro and nano scales have proven their cross-scale applicability. Although many have viewed the prestress requirement as a hindrance to further development of tensegrity structures, this project explores this burgeoning trend by continuing to examine the premise that prestress requirements enable tensegrities to be deployable, tunable, and morphable. This research project will contribute theoretical, computational and experimental capabilities to advance the field of tensegrity structures and metamaterials, and to discover novel modes of tensegrity functionality. The research will be complemented by establishing a flexible educational and outreach program based on curriculum development, training demonstrations, and increasing awareness of these structures by disseminating our findings and tools, in addition to sharing investigator experiences broadly to the public and research communities. The goal of the research is to achieve a deep understanding of tensegrities in order to: (i) design or find tensegrities in any geometry, with the possibility of holes and openings, allowing for application specific tensegrity designs; (ii) use additive manufacturing to conduct rapid prototyping and proof of concept of new designs; (iii) construct and manufacture large-scale application-oriented tensegrity structures (e.g. human-scale), document the experience, and disseminate the challenges and solutions; (iv) design programmable/reprogrammable tensegrity-based metamaterials and study their dynamic characteristics using a Bloch wave analysis framework; and (v) investigate the influence of prestress level to change the size and distribution of band gaps within the tensegrity metamaterial. Specifically, this project should lead to the creation and analysis of elegant Class-1 (“floating struts”) reprogrammable tensegrity metamaterials, and large-scale tensegrity structures which may be used in the design of temporary shelters or structural component protection, among others. As such, it will advance the knowledge base in structures, theoretical and computational mechanics, manufacturing, and materials engineering.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.