CAREER: Harnessing Snapping Instabilities for Shape-Reconfigurable Structures

这笔学院早期职业发展(Career)补助金将支持基础研究，以了解和利用咬合不稳定性来设计具有形状重新配置的机械结构。由不稳定性引起的形状重构具有可重复、快速、广泛、按需触发、耗能最少的特点。这些显着的特点为各种自适应结构和自主机器提供了巨大的潜力，从小型医疗机器人到巨大的可展开航天器。目前的形状可重构结构在可实现的形状、运动和刚度方面都受到限制，这使得它们不适合于一些功能和承载应用。这项研究的结果将提供理论模型、实验数据、模拟工具和新的设计方法，以实现结构在保持刚度以及体积和质量效率的同时，可以广泛地改变其形状。产生的知识将扩大飞行器在偏远和未知环境中的适应能力，并推进空间探索、靶向药物输送和机器人系统的前沿。例如，安装在小卫星群或星座上的可重新配置的传感器和天线结构可以实现低成本、大规模的测量，以便在地球空间和大气科学中进行调查。该项目有一个综合的教育计划，旨在通过将理论、编码、实验和设计经验有机地结合在一门自成一体的课程中，让学生参与主动学习。本研究的目标是弥合曲率分布不均匀的薄壳结构稳定性原理方面的知识差距，以及刺激响应材料行为在整体稳定格局中的作用。因此，本项目的研究思路包括：(1)材料粘弹性引起的亚稳定形状的时间变化、产生和消失。(2)用粘弹性薄壳的热机械加载路径进行多稳定性规划。(3)与气动和水动力表面相关的曲率和扭转分布的薄壳的稳定性分析。(4)通过控制松弛时间失配在连续和折缝离散薄壳结构之间切换。主要的教育计划是重新设计固体力学课程，通过利用学生俱乐部、添加剂制造和在线计算机资源，通过编码、动手实验和设计项目来加强学习。该项目将允许PI推动对主动结构稳定性的理解，并在本科课程中展示新的教学力学模式的可行性。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。

This Faculty Early Career Development (CAREER) grant will support fundamental research in understanding and utilizing snapping instabilities for designing mechanical structures with shape reconfiguration. Shape reconfiguration induced by instabilities is repeatable, fast, extensive, triggered on-demand, and consume minimal energy input. These remarkable characteristics present tremendous potential for a variety of adaptive structures and autonomous machines ranging from small medical robots to giant deployable spacecraft. Current shape-reconfigurable structures are limited in their achievable shapes, motions, and stiffness, making them unsuitable for some functional and load-bearing applications. The outcome of this research will provide theoretical models, experimental data, simulation tools, and new design methods for achieving structures that can extensively vary their shapes while maintaining stiffness as well as volume and mass efficiency. The knowledge generated will expand the capabilities of vehicles to adapt in remote and unknown environments and advance the frontiers of space exploration, targeted drug delivery, and robotic systems. For example, reconfigurable sensor and antenna structures equipped on swarms or constellations of small satellites could enable low-cost, large-scale measurements for inquiry in geospace and atmospheric science. The project has an integrated education plan that aims at engaging students in active learning through organically integrating theory, coding, experiments, and design experience in a self-contained course.The goal of this research is to bridge the knowledge gap in stability principles of thin-shell structures with non-uniform curvature distribution and the role of stimulus-responsive material behavior on the overall stability landscape. Accordingly, the lines of inquiry in this project include: (1) Temporal variation, creation, and disappearance of meta-stable shapes due to material viscoelasticity. (2) Programming of multi-stability by thermo-mechanical load paths in viscoelastic thin-shells. (3) Stability analysis of thin-shells with curvature and twist distributions relevant for aerodynamic and hydrodynamic surfaces. (4) Switching between continuous and creased discrete thin-shell structures via control of relaxation time mismatch. The primary educational initiative is to redesign the Solid Mechanics course to enhance learning through coding, hands-on experimentation, and design projects by leveraging student clubs, additive manufacturing, and online computer resources. This project will allow to PI to push the boundary of understanding on stability of active structures and demonstrate the feasibility of a new model of teaching mechanics in the undergraduate curriculum.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.