Novel 3D+ Multi-axial Preforms for Complex Loaded Composite Applications

复合材料由于具有高强度和低重量，在多个行业的结构应用中取得了显著增长，从而节省了燃料。这被认为是实现行业和政府设定的净零目标之旅的重要组成部分。为了实现这一目标，需要开发新的复合材料，以便更多地将复合材料应用到结构中。具有显著减轻重量潜力的一个关键领域是复杂的承载结构节点，例如用于连接结构组件和传递载荷的凸耳。传统层压复合材料在这一领域试图取代金属材料时面临的主要弱点之一是缺乏贯穿厚度的加固，导致分层和过早失效。3D机织复合材料通过在主要的XYZ方向使用纤维提供了理想的解决方案，“z”或粘结纤维能够承载厚度并抵抗冲击损伤。3D织造的其他好处是能够创建近净形状的预制件和量身定做的性能。尽管3D预制件有很大的潜在好处，但与之相关的还有几个挑战。第一个原因是材料的高度定制化性质，这在3D建筑或编织参数的变化将如何影响最终的复合材料属性方面产生了几个未知因素。这导致大多数3D复合材料都是在统一的架构中制造的，没有充分利用材料的潜力。第二个挑战是缺乏复杂加载条件下所需的+/-45o或离轴纤维。该项目旨在通过开发一种新的3D+材料来解决这一挑战，通过结合3D机织和2D纤维预成型利用这两种技术的优势。该材料将由上下覆盖有离轴2D纤维的3D编织核心组成，创造出一种同时包含复杂加载部件所需的穿透厚度增强和离轴纤维的材料。3D芯将研究预制件内的架构转换的使用，从为最大化主耳主体的机械性能而量身定制的架构，到为耳孔周围的高轴承响应和分层阻力量身定做的架构。通过利用现有技术，可以实现高生产率，同时减少对资本投资的需求，为工业提供可能的快速和高影响的解决方案。这种材料设计方法与均匀铺层的传统方法背道而驰，但在复合材料设计中产生了潜在的阶段性变化，加深了对3D材料的理解，并可能将复合材料应用于以前受到传统铺层限制的结构。

Composite materials have seen significant growth in structural applications across multiple sectors due to the high strength and low weight, enabling fuel savings. This is considered a vital component on the journey to achieving Net Zero targets set by industry and governments. To achieve this goal, development of new composite materials is required to see greater adoption of composites to structures. A key area that offers potential for significant weight saving is complex loaded structural joints such as lugs that are used to connect structural components and transfer loads. One of the primary weaknesses facing traditional laminated composites in their attempt to replace metallics in this area is the lack of through thickness reinforcement, leading to delamination and premature failure.3D woven composites offer a desirable answer to these challenges through use of fibre in the primary xyz direction, with the "z" or binder fibre being able to carry load through the thickness and resist impact damage. Additional benefits for 3D weaving are the ability to create near net shape preforms and tailored properties. Despite the high potential benefits of 3D preforms, there are several challenges associated with it. The first is driven from the high bespoke nature of the material that creates several unknowns in how changes in the 3D architecture or weave parameters will affect the resulting composite properties. This has led to most 3D composites being manufactured in a uniform architecture and not utilising the full potential of the material. The second challenge is the absence of +/-45o or off-axis fibre that is necessary for complex loading conditions.This project aims to address this challenge through developing a new 3D+ material, by utilising the advantages of both technologies through the combination of 3D woven and 2D fibre preforming. The material will consist of a 3D woven core overlaid above and below with off-axis 2D fibre, creating a material that contains both through-thickness reinforcement and off-axis fibres necessary for complex loaded components. The 3D core will investigate the use of architecture transitions within the preform from an architecture tailored to maximise mechanical performance in the main lug body to an architecture tailored for high bearing response and delamination resistance around the lug hole. By utilising existing technologies, a high rate of production is possible with a reduced need for capital investment providing possible rapid and high impact solution for industry. This approach in material design goes against conventional methods of having a homogenised lay-up but generates a potential step change in composite design, a deeper understanding of 3D material, and potential application of composites to structures that have previously been inhibited by traditional lay-ups.