Electronic speckle pattern interferometry (ESPI) for impact damages evaluation on CFP

In this work, it is presented the application of the Electronic Speckle Pattern Interferometry (ESPI) application in the analysis of composites, used in the aeronautic field. Through realtime surface illumination by visible laser (ie 532 nm), the ESPI technique allows the noncontact, non-destructive detection of micro-deformations, micro-cracks, residual stress and delamination. The method is based on recording the surface field differential displacement, due to thermal or mechanical strains. A CCD camera records the whole field deformation into image to be processed. By this technique, it is possible to reveal hidden defects and to evaluate the effective delamination area due, for example, to impact damages. in this study, ESPI technique has been used to evaluate the effective delamination area of damaged Epoxy-Carbon Fibers Composites that have been manufactured by pulsed infusion.