Ductile composites target safety-critical applications

Existing fibre-reinforced polymer composites are known for their high strength and stiffness, but if the materials fail, it can be catastrophic and happen with little warning.

Now, a collaborative research team has been awarded a grant to develop a new generation of ductile fibre-reinforced polymer composites capable of sustaining large deformations without breaking.

The team — from Bristol University’s Advanced Composites Centre for Innovation and Science (ACCIS) and the Composites Centre at Imperial College London — was awarded the £6m six-year grant by the EPSRC.

The team is led by Prof Michael Wisnom at Bristol University and Prof Alexander Bismarck at Imperial College London, and supported by partners, including BAE Systems, dstl, Halliburton, Hexcel, Mouchel, Rolls-Royce and Vestas.

Wisnom, director of ACCIS, said: ’Conventional polymer matrix composites offer high strength and stiffness, low weight, and low susceptibility to fatigue and corrosion, and we are witnessing a rapid expansion of their use in aerospace and other applications. Despite this progress, a fundamental limitation of current composites is their inherent brittleness. Failure can be sudden and catastrophic, with little warning or residual load-carrying capacity.’

Bismarck added: ’High-performance ductile composites will enable robust panels, which dent without significant loss in performance, and super-light, complex structures, which indicate an overload by significant deformation but continue to support load without catastrophic failure. Such materials will provide greater reliability and safety, together with reduced design and maintenance requirements, and longer service life.’

Ensuring materials are ductile will enable them to be used in safety-critical or damage-vulnerable applications, thereby significantly increasing their attractiveness for mass-market applications.