Investigation of alternative excitation sources for vibrothermography

In this study, a mechanical shaker operating at low frequencies is demonstrated to be a viable excitation source for vibrothermography. Additionally, a low-cost transduction approach based on commercially available piezoelectric materials (PZT) is investigated. These PZT transducers are assessed for their excitation efficiency to allow crack detection in metallic structures. Cracks as small as 1 mm are detected using the mechanical shaker regardless of a beam structure orientation or crack location. Although the low-cost PZT-based transduction approach had sufficient excitation power to generate vibration, localized heat generation was not observed at crack locations.
SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, March 8-12, 2009, San Diego, CA, USA
Series: Proceedings of SPIE; no. 7294