22 April 1996 Disbond detection of composite repair patches on concrete structures using laser Doppler vibrometer
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A technique is presented capable of detecting hidden voids underneath a composite patch adhered to concrete structures as reinforcement. The approach is based upon local membrane vibration of a thin panel when it becomes debonded from the host structure. A state-of-the-art laser Doppler vibrometer is used for high-sensitivity, high-speed and noncontact surface vibration detection. The composite repair patch is excited by piezoelectric patch actuators over a wide frequency range to ensure the presence of the local resonance modes in the scanning image. The results show that both boundary and inner disbonds are detectable by this technique, and the location as well as the size of a disbond as small as 0.75 by 1 in2 can be detected when the excitation frequencies are properly selected and the response image is post-processed. The technology has demonstrated its potential for applications such as quality assurance in concrete infrastructure reinforcement and metal structure repair by composite wrapping or patching. It is also appropriate for delamination detection of composite products during manufacturing.
© (1996) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fanping P. Sun, Fanping P. Sun, Craig A. Rogers, Craig A. Rogers, Zaffir A. Chaudhry, Zaffir A. Chaudhry, "Disbond detection of composite repair patches on concrete structures using laser Doppler vibrometer", Proc. SPIE 2719, Smart Structures and Materials 1996: Smart Systems for Bridges, Structures, and Highways, (22 April 1996); doi: 10.1117/12.238835; https://doi.org/10.1117/12.238835

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