Development of signal processing algorithms for delamination detection in composite laminates using non-contact excited Lamb waves.

A novel Signal Processing algorithm based on the combination of a Wavelet Transform Analysis and Image Processing techniques is designed for assessing the delamination detectability of Lamb Waves generated with an innovative fully non-contact system in CFRP plates. Several Damage Indexes are extracted from the wavefields in spatial-time-frequency domain and plotted as surface cartographies to visualise their ability to size and localise artificial delaminations. Results show that the algorithm is efficient for characterising the waves propagation and that sophisticated Image comparison indexes show better ability to detect the artificial defects and to recognise healthy zones despite signal measurement and calculation uncertainties.