3D woven and through thickness reinforced composites

Summary: Laminated composites from dry carbon fibre preforms are increasingly being used to produce primary structures in several industries such as aerospace, automotive and green energy. However, the poor performance in the out-of-plane direction, and delamination has been a cause of concern and requires the careful analysis of load paths to limit out-of plane stress. Furthermore, this has a limiting effect on the design freedom for composite components and could challenge the use of composites for future aerodynamic or structural concepts. Several ‘first-generation’ methods have been proposed to improve out-of-plane performance including z-pinning, selective interlayers and hybrids, protective layers or resin toughening; one method that is becoming increasingly successful is to reinforce composites with a fibre that connects the layers together running from the upper to lower surface of the laminate. This method shows potential but has been limited by the lack of suitable materials available for through-thickness reinforcement where we have hitherto been limited to carbon fibre, glass, basalt, Aramid or other polymeric fibres. Also, there is a limited understanding of the mechanisms involved in out-of-plane rate-dependent response of composite materials. This proposal aims to develop a new understanding of through-thickness reinforcement and to research a methods to produce composites with a through-thickness response which is designer defined. In the future the research will benefit aerospace companies; with the proposed enhanced out-of-plane performance they could potentially design a pressurised blended wing, composite lug arrangement, stringer to skin interface and run-out, buckling critical locations, high impact locations, etc. It will equally improve the performance and reliability of green energy blades or pressure systems associated with energy storage, and the crashworthiness of transport strictures.

 The project will include design and analysis of the through thickness structure, and elements of textile machine development.