Tunable Tensegrity Structures and Metamaterials

张弦梁是在预应力状态下由连续张拉索网络连接的压杆组成的一种特殊结构。这些结构表现出极高的性能，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，张拉整体结构在越来越多的工程应用中得到了应用，包括可展开穹顶、可调谐天线和可持续自适应太阳能电池板等。从几何学的角度来看，十段已被证明是可伸缩的：从大型空间结构到微米和纳米尺度的应用都证明了它们的跨尺度适用性。虽然许多人认为预应力要求阻碍了张拉整体结构的进一步发展，但本项目通过继续研究预应力要求使十段可以展开、可调和可变形的前提来探索这一新兴趋势。这一研究项目将为张拉整体结构和超材料领域的发展提供理论、计算和实验能力，并发现张拉整体功能的新模式。除了向公众和研究社区广泛分享研究人员的经验外，研究还将通过建立一个基于课程开发、培训演示和通过传播我们的发现和工具来提高对这些结构的认识的灵活的教育和推广计划来补充。研究的目标是深入了解十段式，以便：(I)设计或在任何几何形状中找到十段式，具有孔和开口的可能性，以允许特定应用的张拉整体设计；(Ii)使用附加制造进行快速原型制作和新设计的概念验证；(Iii)建造和制造大型面向应用的张拉整体结构(例如人类尺度)，记录经验，并传播挑战和解决方案；(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)研究预应力水平对张拉整体超材料带隙大小和分布的影响。具体地说，该项目应导致创造和分析优雅的1类(“浮动支柱”)可重新编程的张拉整体超材料，以及可用于临时避难所或结构部件保护等设计的大型张拉整体结构。因此，它将推进结构、理论和计算力学、制造和材料工程方面的知识库。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.