CAREER: Performance through Curvature – An Integrated Computational and Experimental Study of the Mechanics of 3D Self-Architected Materials

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。这项教师早期职业发展（Career）资助将侧重于提供对自构建材料的基本机械理解，即三维（3D）结构由自然过程决定的材料，而不是由人类先验地设计的材料。综合计算和实验方法将集中于将几何参数（如曲率）与产生的机械响应相关联，为这类超材料提供基于力学的设计指南和预测工具。在纳米到微尺度上具有3D结构的自构建材料为可扩展的纳米材料提供了一条潜在的途径，这些纳米材料重量轻，具有极高的机械性能，但它们的曲率-力学性能关系在很大程度上仍然未知。该研究项目将通过提供一个知识库来填补这些基础知识空白，该知识库有助于设计具有非周期自构建纳米级特征的新型轻质厘米级材料，这些材料不依赖于先进的增材制造，并且其机械性能可以超越经典建筑材料。揭示自构建材料的力学原理可以为航空航天应用带来先进的轻质结构材料，为国防能力提供保护涂层，以及为弹性工程材料提供设计原则——所有这些都将有助于解决正在进行的材料力学工程挑战。综合教育和推广计划将伴随着研究工作，重点是K-12学生和教育工作者的虚拟和亲自参与，包括增强现实框架，向更广泛的受众，特别是代表性不足的群体（例如西班牙裔）介绍3D建筑材料的设计、制作和实验。该项目的具体目标是揭示自构建材料的几何-力学关系，例如通过spinodal分解过程导出的材料，从而能够预测和理解其机械性能，如刚度、强度和断裂韧性作为曲率分布的函数。扩展负高斯曲率在壳基建筑材料中提供拉伸主导变形的概念，该项目试图通过确定负曲率的方向性如何增强机械性能来显着扩展这种曲率诱导的好处。该方法将整合四个重点，包括相分离自结构材料的可扩展制造，设计和预测理想形态的机械性能的计算框架，以及自然自结构样品和3d打印微尺度原型的纳米力学实验。大多数研究工作将集中在了解曲率依赖的超线性有效特性和自构建材料的破坏机制，以设计轻质但坚韧的可扩展结构材料。该奖项反映了美国国家科学基金会的法定使命，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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).This Faculty Early Career Development (CAREER) grant will focus on providing a fundamental mechanical understanding of self-architected materials, i.e., materials whose three-dimensional (3D) architecture is determined by natural processes as opposed to being designed a priori by humans. The integrated computational and experimental approach will concentrate on relating geometric parameters such as curvature to the resulting mechanical responses, providing mechanics-based design guidelines and predictive tools for this family of metamaterials. Self-architected materials with 3D architectures at the nano-to-microscale present a potential route for scalable nanomaterials that are lightweight and attain extreme mechanical properties, but their curvature-to-mechanical property relation remains largely unknown. This research project will contribute to filling those fundamental knowledge gaps by providing a knowledge base that facilitates the design of new types of lightweight centimeter-scale materials with aperiodic self-architected nanoscale features that do not rely on advanced additive manufacturing, and whose mechanical properties could surpass those of classical architected materials. Uncovering the mechanics of self-architected materials can lead to advanced lightweight structural materials for aerospace applications, protective coatings for defense capabilities, and design principles for resilient engineered materials—all of which would contribute towards solving ongoing mechanics-of-materials engineering challenges. An integrated educational and outreach program will accompany research efforts, focusing on virtual and in-person engagement of K-12 students and educators—including an augmented reality framework—introducing design, fabrication, and experiments on 3D architected materials to a broader audience, particularly to underrepresented (e.g., Hispanic) groups. The specific objective of this project is to uncover geometry-to-mechanics relations for self-architected materials, such as those derived via spinodal decomposition processes, that enable prediction and understanding of their mechanical properties such as their stiffness, strength, and fracture toughness as a function of curvature distribution. Expanding on the concept that negative Gaussian curvature provides stretching-dominated deformation in shell-based architected materials, this project seeks to significantly expand on this curvature-induced benefit by determining how the directionality of negative-curvature enhances the mechanical properties. This approach will integrate four thrusts that include scalable fabrication of the phase-separation self-architected materials, computational frameworks to design and predict the mechanical properties of desirable morphologies, and nanomechanical experiments on both naturally self-architected samples and on 3D-printed microscale prototypes. Most research efforts will concentrate on understanding curvature-dependent beyond-linear effective properties and failure mechanisms of self-architected materials, towards the design of lightweight but tough scalable architected materials.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.