A method for nondestructively evaluating interlaminar bonding during the in-situ thermoplastic tow placement process was developed. In this method, two piezoelectric transducers are oriented in a 'pitch-catch' arrangement. One transducer transmits an ultrasonic signal and the other receives the signal. Each transducer is mounted on a Lucite wedge. The Lucite wedge, in turn, is mounted on a steel wedge. Using this stacked wedge arrangement, a Rayleigh wave is passed between the transducer pair. The pair follows a tow placement head during the consolidation of thermoplastic composite laminates. Poorly bonded regions at the topmost ply will affect the Rayleigh wave speed. The nondestructive sensor function was verified by recording the Rayleigh wave speed for APC-2/PEEK specimens made by tow placement under various processing conditions. The specimens were sectioned and examined under a microscope to verify bond quality. The thickness of the bond line between the top ply and substrate was one measure used to indicate bond quality. Data will be presented which show that there is good agreement between the Rayleigh wave speed and the bond line thickness.
|Original language||English (US)|
|Journal||International SAMPE Symposium and Exhibition (Proceedings)|
|State||Published - Dec 1 1999|
|Event||Proceedings of the 1999 44th International SAMPE Symposium and Exhibition 'Envolving and Revolutionary Technologies for the New Millennium', SAMPE '99 - Long Beach, CA, USA|
Duration: May 23 1999 → May 27 1999