Estudo termográfico de danos por impacto e por indentação quase estática em materiais compósitos tipo sanduíche de uso aeronáutico.

Abstract

This research aims to inspect through the infrared thermography technique damages by drop weight impact and by almost static indentation in aeronautical composite sandwich materials type. The motivation arose from the study of aircraft with structures and elements made of composite materials, where it was found that the load capacity as well as the reliability of the aircraft to perform flights decreases dramatically when they suffer low speed impacts. The methodology used made use of a thermal insulation chamber previously designed for thermographic tests. Drop weight impacts and almost static indentation tests were used to include different energy levels of damage, followed by the thermographic tests of the plates in composite materials with and without damages, where we defined the best heating time to obtain the thermograms. As results, we analyzed the damages in the upper and posterior faces of the thermographic test, where the damages imposed on the composites with drop weight tests were more severe than the damages by almost static indentation. For the thermographic test, thermograms of composites with and without damage were obtained and it was possible to compare them with the damaged composites, where it was observed that damage type of fiber breakage was easily identified. Therefore, it was conclude that it is possible to inspect through thermography in composites sandwiches materials in laboratory environment, but this method did not show viable to detect lower damages impacts of 15.6 J or lower.