CAREER: Tough Architected Concrete Materials: Bio-inspired Design, Manufacturing, and Mechanics

该学院职业发展奖将支持对混凝土的设计和断裂行为的基础研究，这些混凝土具有被称为建筑材料的有目的的安排。混凝土是用于建造民用和能源基础设施的最常见的人造商品。然而，如果没有钢筋，混凝土的抗裂性很低，并且会突然失效。为了改善水泥基材料在机械响应方面的不足，该项目将重点了解和设计更坚固的建筑混凝土，用于关键的民用基础设施和弹性结构应用。通过应用自然产生的坚固材料的概念，如珍珠母(珍珠层)和含有适中成分的骨，新型混凝土复合材料将被设计成具有增强的机械性能，优于普通的未加固混凝土复合材料。通过使用激光工艺和先进的添加剂制造的新型建筑材料的设计和分析，该项目支持更坚固和更具抗损害能力的基础设施组件的新应用，以提高公共安全和繁荣。该项目将结合实验、计算建模和分析方法，为研究和设计这些材料创造新的方法。将研究与教育和推广活动相结合，包括(I)软件开发，(Ii)用于竞赛的混凝土独木舟的添加剂制造，(Iii)开发生物灵感设计课程模块，以及(Iv)参与Día de La Ciencia/科学日双语计划，将促进工程师、用户和学生的使用、采用和教育。该项目的目标是了解和设计建筑混凝土的断裂行为，灵感来自皮质骨中珍珠层和管状骨骼的砖石排列。这项研究计划将使人们对生物材料假想的增韧机理有一个新的理解，用于设计、制造和工程非钢筋混凝土，与普通和纤维增强混凝土相比，具有增强的延展性和断裂韧性。为了实现这些结果，这项研究综合了以下目标：(I)研究天然材料潜在的增韧机理，为合成对应物的设计开发生物启发原理，并设计硬胶凝和软超弹性成分的配方；(Ii)创造有效的制造工艺，使具有故意内部缺陷的形态定制的硬-软多材料组件的制造成为可能；(Iii)为促进设计和制造的添加工艺开发研究和教育软件和刀具路径算法；(Iv)开发适当的实验，以检验建筑材料和硬-软成分的界面的断裂韧性和强度，以及(V)开发一个数值稳健的本构框架，用于模拟软材料和硬材料的架构性组件中的断裂行为。该框架将利用相场方法来捕捉软硬材料主体内的裂纹扩展，并辅之以界面的内聚区模型。该项目将为理解、工程和预测坚韧结构复合材料的机械性能奠定基础，并将为抗裂应用创造新的研究途径和设计可能性。该项目将允许PI推进断裂力学方面的知识基础，并建立他在设计和先进制造方面的长期职业生涯。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 Career Development (CAREER) award will support fundamental research on the design and fracture behavior of concrete with purposeful arrangements known as architected materials. Concrete is the most common human-made commodity used to build civil and energy infrastructure. However, without reinforcement, concrete suffers from low resistance to cracking and abrupt failure. To improve the shortcomings in mechanical response of cement-based materials, this project will focus on understanding and engineering stronger architected concrete for use in critical civil infrastructure and resilient structural applications. By applying concepts from naturally occurring strong materials such as mother-of-pearl (nacre) and bone that contain modest constituents, new types of concrete composites will be engineered with enhanced mechanical properties, superior to everyday unreinforced concrete counterparts. Through the design and analysis of novel construction materials using a laser process and advanced additive manufacturing, this project supports new applications of stronger and more damage-resilient infrastructure components that can enhance public safety and prosperity. The project will combine experimentation, computational modeling, and analytical approaches to create new methods for studying and designing these materials. Integration of research with educational and outreach activities, including (i) software development, (ii) additive manufacturing of concrete canoe for competition, (iii) development of a bio-inspired design course module, and (iv) participation in the bilingual Día de La Ciencia/Science Day program, will facilitate the use, adoption, and education among engineers, users, and students.The goal of this project is to understand and engineer the fracture behavior of architected concrete inspired by the brick-and-mortar arrangement of nacre and tubular arrangement of osteons in cortical bone. The research program will inform a new understanding of hypothesized toughening mechanisms from biological materials for the design, fabrication, and engineering of unreinforced concrete with enhanced ductility and fracture toughness benchmarked against ordinary and fiber-reinforced counterparts. To achieve these outcomes, the research integrates the following objectives: (i) study the underlying toughening mechanisms in natural materials and develop bio-inspired principles for design of synthetic counterparts and engineering the formulations of hard cementitious and soft hyperelastic constituents, (ii) create efficient manufacturing processes that enable fabrication of morphologically tailored hard-soft multi-material assemblies with purposeful internal defects, (iii) develop research and educational software and toolpath algorithms for additive processes that advance the design and fabrication, (iv) develop suitable experimentation for examining fracture toughness and strength of the architected materials and hard-soft constituents’ interfaces, and (v) develop a numerically robust constitutive framework for modeling fracture behavior in architected assemblies of soft and hard materials. The framework will utilize the phase-field approach to capture crack propagation within the bulk of the soft and hard materials, supplemented with a cohesive-zone model for the interfaces. The project will develop a foundation for understanding, engineering, and predicting the mechanical performance of tough architected composites and will generate new research avenues and design possibilities for crack-resilient applications. The project will allow the PI to advance the knowledge base in fracture mechanics and establish his long-term career in design and advanced manufacturing.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.