Abstract
Authors have studied defect imaging technique for a thin plate using a scanning laser source technique, in which Lamb waves are generated with laser emission and received by ultrasonic transducers fixed on the plate. This study described full non-contact imaging technique with air-coupled sensors in the low frequency range of 40 kHz. Moreover, fast defect imaging system using analog peak detectors were developed. Although real-time imaging of defects in a thin plate was realized, unwanted images were obtained in high speed scanning due to reverberations in the plate.
