Electronic speckle pattern interferometry for ndt evaluation of composite materials

Through real-time surface illumination by visible laser (i.e. 532 nm), the Electronic Speckle Pattern Interferometry (ESPI) technique allows the non-contact, non-destructive detection of micro-deformations, micro-cracks, residual stress and delaminations. The measurement range and accuracy is related to the wavelength and the deformation value is measured by half-wavelength laser multiples. With this technique it is possible to reveal hidden defects, cracks and to evaluate the effective delamination area due to, for example, a barely visible impact damage.
ESPI is used to evaluate the effective delaminated area of damaged Epoxy-Carbon Fibers and Glass Fiber Composites after mechanical tests.

Research & Technical staff:
Rocco Alessandra