A computer model for accurate prediction of composite materials behaviour is being developed by researchers to cut cost of air travel.
The model, developed by Imperial College London researchers in cooperation with Airbus, shows how composites – the key component in modern aircraft design – behave after sustaining minor damage.
Knowing the exact behaviour of these materials in various circumstances would allow the designers to build lighter constructions. The lack of such understanding today leads to designers taking precautions and using considerably more material than would be needed. Reducing weight would, in turn, help cut fuel consumption.
“Up to 8 per cent of jet fuel could be saved via weight reduction,” said Silvestre Pinho, leading the research at Imperial College London.
“Excluding military aircraft, this amounts to about 20 million tonnes of fuel, 50 million tonnes of CO2, and £20bn saved annually.”
The project, funded by the Engineering and Physical Sciences Research Council (EPSRC), would enable aircraft designers to scrutinise damage tolerance of materials and develop alternative designs without having to build prototypes and conducting physical test. Such streamlining of the production processes would thus allow for further cost savings due to the simplified research and development.
“One key challenge in designing with composites is that while the physical mechanisms leading to damage develop at a tiny scale, models predicting these mechanisms need to be applied to much larger components,” Silvestre Pinho said. “Nowhere is this challenge greater than in the aerospace industry.”
Composites, about 20 per cent lighter than aluminium, are gaining increasing popularity in the aerospace industry. In addition to being lighter, they are also stronger than most previously prevailing metal-based materials. However, the failure mechanisms affecting them are not as well understood because the industry has several decades more experience using metals.
The new model addresses this problem, with the codes it contains incorporating a range of new insights developed by the Imperial team. In particular, the team’s detailed experimental investigations into different failure mechanisms have enabled damage to be represented for entire aircraft parts.
“We’ve been collaborating with Dr Pinho over a number of years on the development of models for failure of composite structures,” said Morten Ostergaard, Airbus senior expert in Structure Modelling and Non-Linear Finite Element Analysis. “This is a very challenging area and these models constitute a positive contribution to our capability to predict damage in large components.”
Silvestre Pinho has been awarded an EPSRC Engineering Fellowship for further research, focusing on how changes to a composite’s micro-structure would affect a panel’s ability to stop damage spreading.