CAREER: Mechanics of Bio-inspired Multilayered Structures

本学院早期职业发展项目旨在研究多层结构中韧性的尺寸依赖性。层状生物材料优越的力学性能与其层次结构和性质有关。用纳米级结构部件设计这些材料的能力。该项目建立了生物材料增韧机制与坚固结构复合材料设计之间的联系。为了实现这一目标，将使用一种新的实验技术来研究生物和仿生多层材料的增韧机制，该技术可以在纳米尺度上实时测量裂纹的生长。利用韧性起源的知识，冷冻铸造技术将用于制造自然启发的层状混合复合材料。力学模型将开发，以了解增韧机制，如粘弹性裂缝桥接，裂缝挠曲和扭转在生物和仿生多层材料。这些模型将用于优化受自然启发的复合材料的韧性，以及为广泛的结构应用设计定制的复合材料。教育计划有助于并借鉴研究计划。外展项目与非洲的一所大学以及当地的一所社区学院合作。课程开发包括多学科工程课程的归纳式团队教学。强度和韧性是大多数结构材料的重要性能。虽然在开发更强更硬的材料方面已经取得了成功，但如果没有适当的抗断裂性，这些材料几乎不能用作大块结构材料。了解生物材料的力学行为是设计坚固结构材料的关键一步。本项目的目的是研究生物多层材料的韧性。这项基础研究的实验技术和理论成果将对改善美国急需的可持续基础设施产生直接影响。所得模型可用于优化生物基复合材料的性能。教育倡议将通过与当地社区学院和公民学校的合作，让代表性不足的群体参与进来。

This Faculty Early Career Development (CAREER) project aims to study the size-scale dependence of toughness in multilayered structures. The superior mechanical properties of layered biological materials relates to its hierarchical structure and nature?s ability to design these materials with nanoscale structural components. This project establishes a link between toughening mechanisms in biological materials and the design of robust structural composites. To achieve this goal, toughening mechanisms in biological and bio-inspired multilayers will be studied using a novel experimental technique that allows measurement of crack growth in real time at nanometer scale. Using the knowledge of the origin of toughness, a freeze-casting technique will be used to make nature-inspired layered hybrid composites. Mechanics models will be developed to understand the toughening mechanisms such as viscoelastic crack bridging, crack deflections and twisting in biological and bioinspired multilayered materials. The models will be used to optimize the toughness of nature-inspired composites as well as to design tailored composite materials for a wide range of structural applications. The educational plan contributes to and draws upon the research plan. The outreach program collaborates with a university in Africa and locally with a community college. The curriculum development includes inductive team-teaching of multidisciplinary engineering courses. Strength and toughness are both vital properties for most structural materials. Although there has been success in the development of stronger and harder materials, these materials have little to no use as bulk structural materials without appropriate fracture resistance. Understating the mechanical behavior of biological materials is a crucial step in the design of robust structural materials. The objective of this project is to study toughness in biological multilayer materials. The experimental techniques and theoretical findings from this fundamental research will have a direct impact on the improvement of much needed sustainable infrastructure in the United States. The resulting models can be used to optimize the properties of bio-based composite materials. The educational initiatives will involve participation of underrepresented groups through collaborations with local a community college and Citizen schools.