Department of Mechanical Engineering

Optimising performance and improving processes of composite wing structures

robotic placement of composite carbon fibres for an Airbus A350-XWB wing

Challenge

The A350-XWB is the first Airbus airliner to have composite wings, reducing its structural weight compared with the current generation of metallic wings. With over 700 orders for the aircraft, the company has placed great emphasis on the need to optimise performance benefits whilst improving processes by mitigating risk associated with manufacture of the all new wing.

The algorithm, which brought together fundamental knowledge from the university with ideas and practical know-how from industry, is an integral part of a complex optimisation process that allows optimum design of wing skins whilst considering strength, design and manufacturing requirements.

— Head of the Structural Optimisation Technology Centre, Airbus

REF submission

This research was part of our REF 2014 submission for Aeronautical, Mechanical, Chemical and Manufacturing Engineering.

Solution

Ply layout algorithm for optimum design in collaboration with Airbus

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, meaning that 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 colleagues from the Composites Research Unit developed a genetic algorithm that allowed optimum design of composite wing skins, whilst taking into account strength, design and manufacturing requirements.

Low defect manufacture of A350-XWB rear spar in collaboration with GKN Aerospace

The laminated rear spar of an A350-XWB is manufactured by a robot 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, potentially leading to delamination, which can reduce the strength of the complete spar by up to 60 per cent. This can result in parts being rejected or, worse still, compromised component safety.

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.

 

 

 

Benefits and outcomes

The genetic algorithm developed has directly improved the design of composite wing skins and had both an economic and environmental impact. The lighter weight wing saves one tonne of fuel per typical flight compared with current metallic wings and a total fuel saving of 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 $38 million at current fuel prices.

The research analysis of wing spars has led to improved manufacturing processes, minimising the occurrence of defects during fully automated manufacture, and the achievement of satisfactory part quality for current production rates of spars valued at £1 million each when equipped.

Furthermore, the impact of the research has led to Professor Richard Butler being awarded a prestigious Research Chair in composites analysis, jointly funded by GKN Aerospace and the Royal Academy of Engineering.