16 October 2007
16 October 2007
Building aircraft wings with a special aluminium fibre combination makes them nearly immune to metal fatigue, according to the output of research partly carried out at TU Delft
The unusual qualities of this special material (called CentrAl, an abbreviation of Central Reinforced Aluminium) can make a significant contribution to the development of truly energy-efficient, ‘green’ aircraft. Lower fuel consumption and reduction of maintenance costs could lead to worldwide savings as high as €75 billion.
Fatigue is a phenomenon that affects materials after long-term exposure to cyclic loading. As a result of varying loads, fractures eventually occur. Delft say that the new, high-quality CentrAl aluminium constructions are stronger than carbon fibre reinforced plastic (CFRP) constructions that have recently been introduced in aircraft wings such as the Boeing 787 and that, by using CentrAl wing constructions, the weight can be reduced by another 20 per cent compared to CFRP constructions.
The CentrAl concept comprises a central layer of fibre metal laminate (FML), sandwiched between one or more thick layers of high-quality aluminium. This creates a robust construction material which is not only exceptionally strong, but also insensitive to fatigue. The CentrAl technique allows for simple repairs to be carried in a similar way to aluminium construction.
This patented new concept is one of the results of an intensive collaboration between the company GTM Advanced Structures, founded in The Hague in 2004 and specialising in new aircraft materials and constructions, the American aluminium company Alcoa, and the Faculty of Aerospace Engineering of TU Delft.
During a conference in Delft (Conference on Damage Tolerance of Aircraft Structures: 25-28 September 2007), GTM and Alcoa presented the new concept to international experts in the field of metal fatigue and damage sensitivity of aircraft constructions.
Glare FML is already used in the upper fuselage section of the A380.
Toho Tenax is introducing a high-tensile, highly shock-resistant prepreg that incorporates carbon fibre developed for aerospace applications and carbon nanotubes (CNTs).
Thai Flight Training (TFT), a subsidiary of Thai Airways, recently ordered an Airbus A320 door trainer from Spatial Composite Solutions.
NTPT is collaborating with the Ecole polytechnique fédérale de Lausanne - Swiss Centre of Technology (EPFL) and other partners to research discontinuous fibre composite tubes for high performance applications.