Thermal NDT of glass reinforced composite panels for naval applications by means of a linear infrared scanner

Risultato della ricerca: Other


The work describes the development and application of a low cost Thermal NDT set-up to investigate the influence of delamination defects on thick glass fibre reinforced composite laminates simulating typical hull monolithic GRP panels. Two active thermographic techniques have been implemented in particular: a pulsed thermography and a step heating scheme. A 12 mm thick cross-ply panel has been manufactured and delamination defects simulated in two different ways: by embedding patches of folded Teflon sheets, and by drilling flat bottomed back holes. A number of defects was then positioned at three different depths form the scanned surfaces, measuring ¼, ½ and ¾ of the laminate thickness. A reflection set-up was adopted, with an external heat source consisting of 1500 W halogen lamps. Results have evidenced the possibility to use the proposed cheap thermographic set-up, suitable to operate also in boatyard environments, to detected non-visible delamination type defects in thick GRP laminate skins. A fine tuning of the operational parameters is though essential in order to better identify defects features and to discern the influence of other factors such as surface finish.
Lingua originaleEnglish
Numero di pagine10
Stato di pubblicazionePublished - 2009


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