Quantitative subsurface defect detection in composite materials using a non-contact ultrasonic system
- Autori: Cerniglia, D.; Djordjevic, B.; Nigrelli, V.
- Anno di pubblicazione: 2001
- Tipologia: eedings
- Parole Chiave: Engineering (all)
- OA Link: http://hdl.handle.net/10447/201567
The results of an experimental study conducted to detect subsurface defects in a thick Gr/PPS composite test sample using a non-contact ultrasonic system are presented. Surface waves are generated by a pulsed laser and detected by a air-coupled capacitance transducer. By controlling the surface wave wavelength through a shadow mask, it is possible to control surface wave penetration depth in the sample. Surface wave peak-to-peak amplitude is related to the near-surface material condition. Results indicate that signal amplitude decreases as the width of the defect increases and an approximately linear relation can be deduced.