NDTnet 1998 Aug, Vol.3 No.8

Abstract

During take-off and landing the wheels of modem aircraft are subjected to a great deal of stress. New types of high-performance brake systems as well as aggressive environmental influences result in the wheels being operated closer and closer to the limits imposed by their design. These conditions as well as higher requirements regarding safety and quality assurance have made it necessary to test wheels on aircraft much more detailed than in the past.

Until now wheels are usually tested by die penetration. This test method visualizes defects which can be seen on the surface of the material. It is, however, known that the test results depend greatly on the respective tester's ability to concentrate and how tired he is. Therefore aircraft wheels have been tested by eddy-current with an emphasis on finding surface defects on the wheel's running tread.

An increase of environmental corrosive aggression in conjunction with the extreme stress during take-off and landing causes defects in high-performance aluminum materials which endanger the wheel's operational safety not only from its surface. Thus, tests have to be carried out on the interior surface of the wheel as well in those areas which are not directly accessible (grooves, bore holes, webs, threaded joints, etc.). In these areas increasing numbers of fatigue cracks or changes in the material which weaken its hardness are diagnosed.

One therefore derives from the current state of technical development and the resulting requirements the task to find as many defects as possible by using eddy-current testing that fits just these requirements.As part of the development of powerful computer systems, it has become possible to realize image-providing eddy-current test systems which today are able to test the highest throughput not only for surface defects but also for interior or hidden defects. Today, various evaluation alogarithms and types of depiction facilitate the reliable detection of flaws originating from Lhe wheel's interior surface or internal bore holes. Here automated evaluation is a desirable goal which, to a large degree, can already be achieved today.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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