Interference fit fastener inspection using sonic thermography

Abstract

This paper reports on an experimental study addressing the application of sonic thermography to the characterisation of interference fit levels in fastened metallic plates. The technique uses high intensity acoustic waves to induce frictional heating at defect locations. In the case of poorly fitted interference fasteners, the acoustic waves induce relative motion between the fastener and host, causing frictional heating that is detected with a thermal imaging system. Results are shown to demonstrate the efficacy of the approach.

Keywords:

• Infrared
• interference fit
• non-destructive evaluation
• sonic IR
• sonic thermography.

Additional information

Notes on contributors

K A Tsoi

Dr Kelly Tsoi completed a BSc (Hons) in Physics at the University of Melbourne in 1995. She commenced work in the Airframes and Engines division of the Aeronautical and Maritime Research Laboratory in 1996, and has worked on methods of fatigue life enhancement using smart materials. In 1998 she commenced studies at the University of Sydney and the Katholieke Universitait Leuven in Belgium, which led to the completion of a PhD in 2002. She is currently involved in the development of active thermographic techniques for non-destructive evaluation and the development of in-situ structural health monitoring techniques.

N Rajic

Dr Nik Rajic received a BEng (Hons) in Mechanical Engineering from the University of Melbourne in 1989. He joined the Structures Division at the Aeronautical Research Laboratory in 1991, and in 1992 undertook studies at Monash University, which led to the completion of a PhD in 1995. He has since contributed to research on fatigue-life extension techniques, thermoelastic stress analysis, thermoplasticity, thermographic non-destructive evaluation, and in-situ structural health monitoring techniques based on smart structures principles.