NDT OF COMPOSITES: Comparative study of different non-destructive testing techniques in the characterisation and quantification of the damage effects in carbon-epoxy laminates

Abstract

In this work, three different non-destructive testing techniques, electronic speckle pattern interferometry (ESPI), shearography and ultrasonic C-scan, have been used to inspect damaged laminate composites. The first goalof this article is to compare the usefulness and effectiveness of the referred techniques. Qualitative and quantitative information relating to defects will be used to scale the advantages and disadvantages of the mentioned techniques. Important parameters like size, shape and precise location of damages will be considered. In this work, results are shown for two kind of carbon-epoxy laminated structures presenting [0,90,0,90] 2 s and [0,90] 8 stacking sequence of plies that were submitted to impact energies of 1.5J, 2J, 2.5J and 3J, corresponding to loads of 2160 N, 2430 N, 2700 N and 2970 N, respectively. The NDT experimental results have also provided useful information to determine which of the two-ply orientations presents higher impact resistance.