Damage tolerant ultralightweight mechanical metamaterials (MMs) for the next-generation large scale all-electric aircrafts

2018年，航空排放量占英国温室气体排放量的7%，这表明电气化可能对航空业的脱碳产生重大影响。大规模全电飞机结构的成功实现在很大程度上取决于高性能结构材料的突破，以克服传统材料面临的各种限制。机械超材料（Mechanical Metamaterials，缩写为MEM）是一组人造结构材料，可以通过几何排列而不是材料特性来实现前所未有的机械性能和多功能性。该研究旨在建立一种可行的设计路线，为下一代大型全电动飞机制造损伤容限超轻机械超材料（MEMS）。损伤容限是高性能结构材料的基本要求。结构材料预期（i）以渐进方式失效，可以对失效事件发出警告，以及（ii）在存在缺陷的情况下具有良好的承载能力。天然细胞材料，如海洋贻贝、蜂窝、木材、小梁骨、植物薄壁组织和海绵，受益于其内部微观结构内的无序性，以实现高度损伤耐受行为。受此启发，本研究的目标是（1）通过将受控的无序度工程化到初始周期性有序的超材料系统中，为损伤容限超轻材料开辟一条新的设计途径。该计划将得到新的、机械信息数据驱动的方法的支持，这些方法可以调整飞机内部的无序分布，（2）设计具有高损伤容限的新型超轻型飞机，（3）建立高性能、损伤容限超轻型飞机的设计原则，以及（4）评估全电动飞机结构的多功能应用的有效性。

Aviation emissions accounted for 7% of UK Greenhouse Gas emissions in 2018, which suggests electrification could have a large impact on decarbonizing the aviation sector. The successful realization of large scale all-electric aircraft architectures is heavily dependent on breakthrough in high-performance structural materials to overcome the various limitations faced by the conventional materials. Mechanical metamaterials (MMs) are a group of man-made architected materials that can be tailored to achieve unprecedented mechanical properties and multifunctionality through geometric arrangements rather than material properties of the constituents. The proposed research aims to establish a feasible design route to create damage tolerant ultralightweight mechanical metamaterials (MMs) for the next-generation large scale all-electric aircrafts. Damage tolerance is a fundamental requirement for high performance structural materials. Structural materials are expected to (i) fail in a progressive manner that can give warning to failure events, and (ii) have good load bearing capacity with presence of flaws. Natural cellular materials, such as marine mussels, honeycombs, woods, trabecular bones, plant parenchyma and sponges, benefit from the disorderliness within their internal microstructures to achieve highly damage tolerant behaviours. Inspired by this, the objectives of this research are to (1) open up a novel design pathway for damage tolerant ultralightweight MMs by engineering controlled degrees of disorderliness into initially periodic, ordered metamaterial systems. The initiative will be supported by novel, mechanics informed data-driven approaches that can tune the distribution of disorderliness within the MMs, (2) design new classes of ultralightweight MMs with high damage tolerance, (3) establish the design principles of high performance, damage tolerant ultralightweight MMs, and (4) evaluate the effectiveness for multifunctional applications of MMs for all-electric aircraft architectures.