Next Generation Fibre-Reinforced Composites: a Full Scale Redesign for Compression

高性能纤维增强聚合物复合材料是目前最先进的轻质结构，其在从航空航天到体育用品的广泛应用中的使用呈指数级增长。它们具有卓越的机械性能：高强度、高刚性、低重量、低疲劳和低腐蚀敏感性。纤维形式的高强度、高硬度材料的使用减少了过早脆性破坏的倾向，使部件能够在低或中等温度下成形，并使各向异性设计能够针对主要承载需求。纤维在单轴拉伸方面特别有效，但在压缩下，复合材料遭受一系列破坏，通常与纤维微屈曲或扭结有关，与基质或界面问题有关；这些机制在不同的物理长度尺度上以复杂的方式耦合。通常，这些类型的失效决定了复合材料的实际使用，并将设计极限设置为远低于组成纤维的预期固有性能。另一方面，新的成分和工艺正在变得可用，它们使得能够在比以前可能的更大的长度范围内控制的复合材料结构的定向组装。因此，原则上，复合材料应该重新设计，以利用这些机会抑制或重新引导压缩破坏过程。自然材质，如木材和骨骼，是完全分层的，具有精确的结构特征，以每一种可能的放大倍数进行解析。人造复合材料缺乏这种灵巧性，但可以利用内在的优势成分。可视化、计算和控制结构的能力日益增强，包括定量精度，这将使新一代复合材料得以开发。该计划的目标是通过从基本原理出发，利用材料、加工、表征和机械过程建模方面的最新发展，通过设计这种分级压缩系统来实现纤维的全部内在潜力。该计划专注于提高复合材料在压缩中的绝对性能的挑战，这既是为了解决当前材料的实际限制，也是为了展示定量分级材料设计的价值。在本方案期间开发的工具和材料将在其他一系列情况下发挥作用。这项工作将开发和嵌入每个长度的结构，从基质的分子，到最终组件的铺设，使用新的成分和新的架构，设计了一个新的分析框架。该计划将受益于核心项目条款中高度创造性和跨学科的方法，并得到主要国际顾问和合作者的贡献。一个广泛的工业伙伴团体将在方案期间设计的概念示范器的基础上，为该项目作出贡献，并帮助开发产出。科技成果将在国内和国际上广泛传播，有助于确保英国在这一关键领域的领先地位。

High performance fibre-reinforced polymer composites are the current state-of-the-art for lightweight structures and their use is rising exponentially in a wide range of applications from aerospace to sporting goods. They offer outstanding mechanical properties: high strength and stiffness, low weight, and low susceptibility to fatigue and corrosion. The use of high strength, high stiffness materials in fibre form mitigates the tendency for premature brittle failure, enables components to be formed at low or moderate temperatures, and enables anisotropic designs to target the primary load-carrying demands. Fibres are particularly efficient in uniaxial tension but, under compression, composites suffer a range of failures typically associated with fibre micro-buckling or kinking, linked to matrix or interfacial issues; these mechanisms couple in a complicated way at a variety of physical lengthscales. Often, these types of failure determine the practical usage of composites and set design limits well below the expected intrinsic performance of the constituent fibres. On the other hand, new constituents and processes are becoming available that enable the directed assembly of composite structures, controlled across a much wider range of lengthscales than previously possible. In principle, then, composite materials should be redesigned to take advantage of these opportunities to supress or redirect the failure process in compression. Natural materials, such as wood and bone, are fully hierarchical, with precise structural features resolved at every possible magnification. Artificial composites lack this dexterity but can exploit intrinsically superior constituents. The increasing ability to visualise, calculate, and control structures, including with quantitative precision, will allow a new generation of composite materials to be developed. The ambition is to realise the full intrinsic potential of the fibres by designing such hierarchical systems for compression, from first principles, exploiting the latest developments in materials, processing, characterisation, and modelling of mechanistic processes.This programme focusses on the challenge of improving the absolute performance of composites in compression, both to address practical limitations of current materials, and as a demonstration of the value of quantitative hierarchical materials design. Tools and materials developed during this programme will be useful in a range of other contexts. The work will develop and embed structure at every lengthscale from the molecules of the matrix, to the lay-up of final components, using new constituents and new architectures, designed with a new analytical framework. The programme will benefit from a highly creative and interdisciplinary approach amongst the core project term, amplified by contributions from leading international advisors and collaborators. An extensive group of industrial partners will contribute to the project, and help to develop the outputs, building on concept demonstrators designed during the programme. The scientific and technical results will be widely disseminated nationally and internationally, helping to ensure UK leadership in this key field.