The A350-XWB was the first Airbus airliner to use composite wings, making them structurally lighter than airliners with metallic wings. With over 700 orders for the aircraft, the company was keen to optimise processes while mitigating risk associated with manufacturing the new wing.
Collaboration with Airbus and GKN Aerospace
A 30 metre wing is made up of laminated skin panels, varying from over 100 layers thick in some panels to ten layers thick in others. Both the laminate thickness in each panel and the fibre orientation of each layer within the laminate must be considered for an optimum design. Professor Richard Butler and a team of researchers developed a genetic algorithm to optimise the design of composite wing skins while taking into account strength, design and manufacturing requirements.
The laminated rear spar of an A350-XWB is manufactured by robots at GKN Aerospace using a layering method of composite fibres. If a fault occurs during this process there is a risk of buckling or wrinkling in the layers, leading to delamination. This can reduce the strength of the complete spar by up to 60% and compromise component safety. Defective parts are rejected, costing the company time and money.
Our researchers analysed the laminate consolidation process for the wing spars and adapted geological folding models, developed at the University, to predict fibre wrinkling during the manufacture of laminated composite components.
Lighter wings create fuel savings
The new genetic algorithm directly improved the design of composite wing skins and had both an economic and environmental impact. The lighter weight wing saved one tonne of fuel per typical flight compared to airliners with metallic wings. The total fuel saving amounts to around 40,000 tonnes over the design life of each aircraft. This represents a reduction in CO2 emissions of 126,000 tonnes and a cost saving of more than £28 million at current fuel prices.
The research analysis of wing spars has led to improved manufacturing processes. It's helped to minimise defects occurring during manufacture, as well as achieving satisfactory part quality for production rates of spars with a final value of £1 million each.
This research was part of our REF 2014 submission for Aeronautical, Mechanical, Chemical and Manufacturing Engineering.