Engineering resilient hierarchical metamaterials

超材料可以设计成多功能(提供常规工程材料无法实现的特性组合)，并占据以前空白的材料特性空间(如高硬度、高强度和低密度下的断裂韧性)。在具有可伸缩性的大面积成瘾制造方面的最新进展，以前不能通过双光子聚合或传统的立体光刻实现，有望显著减少制造时间，这将加速工业吸收。虽然最近在理解分层设计原则如何影响机械稳健性和损伤容限方面取得了重大进展，但仍有许多差距。例如，如何通过增韧机制抑制断裂；减少结构不稳定性；以及如何优化高韧性，同时在低密度下保持高硬度和高强度。这项拟议的项目将重点研究超材料的延性断裂和疲劳损伤响应。理论建模(均匀化)、实验和数值模拟(FE)将用于将微观结构现象与可观察到的宏观变形响应和块体特性联系起来。其目的是对在多个长度尺度上发展的损伤机制之间的相互作用有一个基本的了解，制定获得其性能界限的理论方法，并为这些材料的设计提供指导。

Metamaterials can be engineered to be multifunctional (offering combinations of properties not achievable by conventional engineering materials) and occupy regions of material property space (such as high stiffness, strength and fracture toughness at low density) that were previously empty. Recent advances in `large-area addictive manufacturing with scalability, not previously achievable by two-photon polymerization or traditional stereolithography, promise significantly reduced manufacturing time, which will speed up industrial uptake. Whilst significant recent progress had been made to understand how the principles of hierarchical design affect mechanical robustness and damage tolerance, there are also many gaps. For example, on how to suppress fracture through toughening mechanisms; reduction of structural instabilities; and, how to optimise for high toughness, yet maintain a high stiffness and strength at low density. This proposed project will focus on the ductile fracture and fatigue damage response of metamaterials. Theoretical modelling (homogenization), experiments and numerical simulations (FE) will be used to link microstructural phenomena to observable macroscopic deformation response and bulk properties. The aim is to obtain a fundamental understanding of the interactions between damage mechanisms that develop at multiple length scales, formulate theoretical methods for obtaining bounds on their properties, and provide guidelines for design with these materials.