High Performance Ductile Composite Technology (HiPerDuCT)

Conventional composites such as carbon fibre reinforced plastics have outstanding mechanical properties: high strength and stiffness, low weight, and low susceptibility to fatigue and corrosion. Composites are truly the materials of the future, their properties can be tailored to particular applications and capabilities for sensing, changing shape or self healing can also be included. Their use is rising exponentially, continuing to replace or augment traditional materials. A key example is the construction of new large aircraft, such as the Boeing 787 and Airbus A350, mainly from carbon fibre composites. At the same time, there is rapid expansion of composite use in applications such as wind turbine blades, sporting goods and civil engineering infrastructure.Despite this progress, a fundamental and as yet unresolved limitation of current composites is their inherent brittleness. Failure is usually sudden and catastrophic, with little or no warning or capacity to carry load afterwards. A related problem is their susceptibility to impact damage, which can drastically reduce the strength, without any visible warning. Structures that look fine can fail suddenly at loads much lower than expected. As a result complex maintenance procedures are required and a significantly greater safety margin than for other materials. Our vision is to create a paradigm shift by realising a new generation of high performance composites that overcome the key limitation of conventional composites: their inherent lack of ductility. We will design, manufacture and evaluate a range of composite systems with the ability to fail gradually, undergoing large deformations whilst still carrying load. Energy will be absorbed by ductile or pseudo-ductile response, analogous to yielding in metals, with strength and stiffness maintained, and clear evidence of damage. This will eliminate the need for very low design strains to cater for barely visible impact damage, providing a step change in composite performance, as well as overcoming the intrinsic brittleness that is a major barrier to their wider adoption. These materials will provide greater reliability and safety, together with reduced design and maintenance requirements, and longer service life. True ductility will allow new manufacturing methods, such as press forming, that offer high volumes and greater flexibility.To achieve such an ambitious outcome will require a concerted effort to develop new composite constituents and exploit novel architectures. The programme will scope, prioritise, develop, and combine these approaches, to achieve High Performance Ductile Composite Technology (HiPerDuCT).