MICHAEL PHELAN / LONDON
Airbus UK is leading a new Civil Aircraft Structural Composites Application Development and Exploitation (CASCADE) project designed to lead to more composite technology being incorporated in Airbus wings.
The £5.2 million ($7.9 million) project, 50% funded by the UK Department of Trade and Industry, aims to streamline manufacturing processes developed for an earlier composite wing research project, AMCAPS II (Flight International, 21-27 March 2000).
Due for completion in July 2004, the two-year CASCADE programme is in partnership with Advanced Composite Group, INBIS, Qinetiq and W & J Tod, and aims to produce "small demonstrator" components, according to Airbus.
UK research agency Qinetiq is receiving the bulk of the subcontracted work from Airbus UK and £1.8 million funding from the DTI for the development of faster and cheaper composite production methods. Qinetiq's group leader for CASCADE, Dr Debra Pullen, says the major challenges in composite wing component manufacture are manpower costs. Qinetiq's focus is "integrating the processing methods and materials developed" in the earlier programmes, says Pullen.
Improvements in resin infusion production methods promise to reduce costs. Resin infusion, more widely used in marine applications, differs from the pre-impregnated composite lay-up construction methods more traditional in aerospace in that the fibres are laid up as a dry fabric stack and the matrix resin is drawn through the stack by a vacuum generator. One of the challenges, according to Pullen, is to maintain consistent bonding integrity for resin infused composites with high carbonfibre content.
"Fibre contents of 55-58% have already been achieved," says Pullen, with 60% the target. Traditional bonding techniques developed for glassfibre composites in marine applications need to be adapted to carbonfibre bonding, she adds.
Qinetiq is also studying non-crimp fabric composite materials, which consist of uni-directional fibre layers cross stitched with carbon or polyester through-plys, which can reduce the risk of delamination in lay-ups.
Source: Flight International
