Pulsed eddy current imager for the enhanced non destructive evaluation of aeronautical riveted assemblies

In this paper, an original pulsed eddy current (EC) imaging system dedicated to the enhanced non-destructive evaluation (NDE) of aeronautical riveted is presented. The system aims to combine the advantages of the pulsed eddy current (PEC) sensors with those of EC imaging devices. The system is based on the combination of a PEC inducer, and a magneto-optical (MO) set-up used to measure the magnetic two-dimensional impulse response of the part under evaluation. The obtained data are in the form of a temporal succession of high resolution EC images, enabling both the spatial and temporal EC characterization of the part. The system is implemented here on aluminum riveted assemblies featuring calibrated defects placed next to rivets. The study demonstrates the relevance of the PEC imager to separate defects signature from rivets and to characterize the detected defects thanks to the extraction of space-time features from the provided data.