New method to test aircraft components
Scientists in Germany and the UK are developing a new method for testing aircraft components that should make air travel both safer and cheaper. The team's objective is to develop state-of-the-art computer modelling programs that show how aircraft components react under the stresses of flying. This could then replace the costly mechanical testing that components currently undergo. The process whereby small cracks inherent in the metal components making up aircraft engines grow over time is called metal fatigue, or 'fatigue crack growth'. The phenomenon has in the past been the cause of tragic accidents, such as the 1989 United Airlines crash in the US when 112 people died. Investigators found that the piece of metal holding the fan blades together had shattered, destroying the craft's hydraulics, and causing it to cartwheel across the tarmac as it tried to land. 'In any aircraft journey the parts of the engine go through a complex combination of stresses and vibrations. We need to know how the inherent cracks in the metal are going to be affected, says lead researcher Jie Tong from the University of Portsmouth. 'The safety of aircraft depends on engineers knowing when the cracks are going to become a problem so that plans can be made to replace components during regular inspection cycles. The scheduling of these inspections critically depends on the precise knowledge of crack growth mechanisms and growth rate,' says Professor Tong. According to the University of Siegen, up to 90% of a component's lifetime is spent in the stage of the initiation and early growth of short cracks. Materials scientists at the German university will examine dislocation structure and other microscopic changes in components using a powerful transmission microscope. 'This work will not only improve air safety, but also reduce the maintenance cost - currently running into billions of dollars worldwide - which means cheaper and safer air travel for all,' says Professor Tong.
Countries
Germany, United Kingdom