A non-contact ultrasonic system using a pulsed laser source and a wideband 1-3 connectivity PZT/epoxy composite transducer as a receiver has been used to produce images of defects in a variety of materials. Using both time and frequency information, through transmission images have been formed of delaminations and machined defects in both carbon fibre reinforced polymer (CFRP) and pultruded glass-fibre reinforced composites. Lamb waves have also been used to reconstruct tomographic images using a filtered back projection algorithm, for defects in thin plates of CFRP and Perspex.
- imaging of defects
- piezoelectric air-coupled transducers
- ultrasonic imaging
- laser generation
Wright, WMD., Hutchins, D. A., Hayward, G., & Gachagan, A. (1996). Ultrasonic imaging using laser generation and piezoelectric air- coupled detection. Ultrasonics, 34 (2-5), 405-409. https://doi.org/10.1016/0041-624X(95)00119-N