CAREER: Auxetic Lattice Reinforcing Metamaterial Architectures for a New Class of Concrete Metastructures

该学院早期职业发展（Career）项目将利用建筑超材料的独特机械性能，创造一种新型的钢筋混凝土结构（即超结构），其机械性能（即强度、延展性和能量吸收）优于现有的结构。钢筋混凝土是世界上最常用的结构材料之一，因此其性能的重大改进具有变革性的社会意义，例如降低成本，以及提高结构的质量和能力。钢筋混凝土超结构，无论是直接设计或受建筑超材料的影响，结合材料和建筑以独特的方式实现以前无法实现的性能。该项目的教育和推广计划将通过制定具有有效科学内容的教育策略，提高各级得不到充分服务的双语学生的科学素养。它将通过波士顿科学博物馆的“工程是基础”项目吸引小学生，并将通过将教育活动与工业工作联系起来，促进知识向工业的转移。这项研究依赖于一种新的混凝土约束技术，这种技术可以通过建筑超材料中发现的独特力学特性来实现。研究方法是采用负泊松比（负泊松比）超材料晶格结构作为钢筋，并展示这种新型限氧混凝土在改善建筑结构系统内构件性能方面的实用性。通过混凝土基体和塑性晶格的材料合成，将形成一种新的复合材料，并在非弹性范围内建立一种新的塑性约束模型。为了实现这一目标，将进行综合计算和实验研究计划。最后，为了提高建筑结构的限制混凝土，研究计划将采用数字制造和自动化制造技术来有效地制造限制混凝土结构构件。柱和剪力墙耦合梁将被设计和实验测试，以证明新的自限钢筋混凝土的能力，旨在提高强度和延性，以及增加抗剪强度和能量吸收。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 Faculty Early Career Development (CAREER) program will exploit unique mechanical properties of architected metamaterials to create a new class of reinforced concrete structures (i.e., metastructures) with mechanical properties (i.e., strength, ductility and energy absorption) superior to those available today. Reinforced concrete is among the most commonly used structural materials in the world and therefore significant improvements in its properties have transformative societal implications such as reducing costs, as well as increasing the quality and capabilities of structures. Reinforced concrete metastructures, either designed directly from or influenced by architected metamaterials, combine material and architecture in unique ways to achieve previously unattainable properties. The education and outreach plan of this program will enhance the scientific literacy of underserved bilingual students at all levels by developing educational strategies with effective scientific content. It will engage elementary students through the “Engineering is Elementary” program of the Boston Museum of Science and will also facilitate transfer of knowledge to the industry by linking educational activities to industrial work.The research relies on a novel concrete confinement technique which can be achieved through a unique mechanical property found in architected metamaterials. The research approach is to employ auxetic (negative Poisson’s ratio) metamaterial lattice architectures as reinforcement and demonstrate the utility of this new auxetically confined concrete for improving the performance of members within a building structural system. Through material synthesis of the concrete matrix and the auxetic lattice, a new composite will be created and a new auxetic confinement model will be developed in the inelastic range. To achieve this, an integrated computational and experimental research program will be pursued. Finally, to upscale the auxetically confined concrete for building structures, the research program will employ digital fabrication and automated manufacturing techniques to efficiently manufacture auxetically confined concrete structural members. Columns and shear wall coupling beams will be designed and experimentally tested to demonstrate the capabilities of the new auxetically confined reinforced concrete, aiming at improved strength and ductility as well as increased shear strength and energy absorption.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.