Getting the green light — bio-composite racing car

Materials World magazine
,
1 Apr 2009

A UK-based research consortium from the Universities of Ulster and Warwick is building an eco-friendly Formula 3 racing car. Dr Edward Archer from the School of Engineering at the University of Ulster describes the project.

Project founders Warwick Innovative Manufacturing Research Centre, UK, intend to prove to industry that it is possible to build a competitive racing car using environmentally sustainable components. This research is timely considering the recent problems in Formula 1 (F1)stemming from the high costs of running competitive motor racing teams, and doubts in sponsors’ minds over the commercial value of involvement.

The team has been building an ‘organic’ car. One of the goals is to save fuel by using composite materials to reduce weight. Composite material technology in motor sport has developed enormously since 1981 when McLaren unveiled its first carbon-composite MP4-1 F1 car. To this end, researchers have entered into a project with the Engineering Composites Research Centre at the University of Ulster (ECRE), UK, to manufacture lightweight composite components, specifically aerodynamic barge boards. The Centre uses technologies primarily developed for aerospace composites.

Speed by design

The primary function of the ECRE is to investigate the inter-relationships between the processing parameters and performance of polymers and composite materials. The Centre has the capability to take high performance textile yarns, such as carbon, Aramid, glass and natural fibres through to complex 3D woven technical textile structures, impregnating them with resins, either thermosetting or thermoplastic, to produce high performance components.

Recent research into the processing parameters of bio-resins, in collaboration with Dr Julie Soden from the Art & Design Research Institute at Ulster, has created the possibility of producing green composite structures. The process uses 3D flax yarn preforms with liquid moulding technology.

Traditional methods of composite material manufacture are considered expensive for composite component production, especially for sports applications such as Formula Student. This is due to the high capital cost autoclaves, the inert gas used to transfer pressure and heat to the lay-up, cold storage of pre-impregnated fabric and the labour needed to prepare the reinforcement structures. Cost remains a major factor in preventing the wider use of these materials in place of metallic alloys.

Liquid injection techniques, however, have the potential for mass production and to reduce costs, especially when used in conjunction with 3D woven textile preforms which do not require costly and time consuming trim and debulk. Liquid moulding is complementary to the use of 3D woven flax preforms.

The Engineering Composites Research Centre has implemented a Vacuum Assisted Resin Transfer Moulding (VARTM) system for the bio-resins which uses vacuum pressure to both consolidate the fabric and suck resin into the mould. This system differs from the pre-preg as no resin is deposited on the fabric until it is inside the mould.

Graeme Stewart from the research team at Ulster explains the challenges presents, as the ability of the VARTM system to fully impregnate the woven preform, and impart strength and aesthetic properties, is largely governed by the resin viscosity. ‘The bio-resins are a new development and control of viscosity is not as well understood as with the tried aerospace epoxy resins’.

Stitching up

Dr Alistair McIlhagger, Lecturer at the School of Electrical and Mechanical Engineering at the University of Ulster, believes Northern Ireland’s embattled textile weaving industry could be given a new lease of life thanks to breakthroughs by engineers at Ulster. Scientists at ECRE are leading research in 3D weaving of carbon fibre composite materials, which are being developed to make components for the next generation of aircraft.

McIlhagger says, ‘3D weaving came from the textile industry. We were able to use a traditional loom, with modifications, to weave the new materials. There is a skills base in textile weaving in Northern Ireland that we can tap into’. However, he admits that moving into bio-composites is a huge challenge for the textiles industry.

Ulster’s research into woven fabric and next-generation composite materials using carbon fibre and high grade resin has been driven by the aerospace industry, which is keen to develop lighter, more cost-effective and cleaner aircraft. However, scientists at Ulster have successfully harnessed this technology and adapted it to develop, design, manufacture and test components made from bio- resin and 3D woven flax composite materials for non-aerospace applications.

A potential outlet for the materials developed under the programme is body panels for the Ulster Formula Student car. The University has been competing in the worldwide university-based competition, Formula Student, since 2001. Run in the UK by the Institute of Mechanical Engineers, the competition challenges students to design, build and race a single-seat car.

Programme Leader Dr Justin Quinn of the School of Engineering believes that the key skills learned at the Centre are key for students to move successfully from academia to industry. ‘Environmental awareness in design must be an integral part of industry. The Formula Student programme has wide coverage in both industry and academia, exposing students to eco-design and the use of bio-composites in a performance vehicle.’ The University of Ulster, Jordanstown Campus Racing (09) team is in the final stages of bodywork design and some bio-composite will be used in the car.