IR THERMOGRAPHY IN NDE OF CARBON-GLASS LAMINATE

Abstract

The article presents a comparison of the effects of using active IR Thermography technique for the tests of composite aircraft structures. The most important question arising together with an increased use of composites in aviation industry is to work out a method, which would allow identification of the technological defects, and damages appeared in the process of the aircraft use. Non-destructive testing which has been used so far to identify defects in the aircraft structure made from metallic materials has a quite limited application in case of composite structures. With the growing use of composites in the aviation industry, a necessity appears to work out a method allowing early identification of technological defects and damages appeared in the process of the aircraft operation. It could be the active thermography techniques used for the thin walled elements tests, such as wing and fuselage skin, with the focus on fractures and delamination. Light composite aircraft have been built for a many of years, however, the annual flight hours of these aircraft are incomparably lower than those of the aircraft used in air transport. In group of light aircraft, the less important elements were made of composites regarding the strength of the whole construction. When the newest aircraft were introduced, with most important construction elements such as the fuselage, wings, horizontal and vertical tails, doors and the interior made of composite materials, it was expected that the increased amount of the annual flight hours (more than 3000 hours) and the expected airliner lifetime (about 30 000 hours) would soon cause degradation of the mechanical properties of the composites following from the progress of ageing of the composite structures. The obtained research results bring closer the problem of selection of the well-fitted non-destructive testing method depending on the kind of the diagnosed construction.