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A Nonlinear Acoustic Technique for Crack Detection in Metallic Structures
Full text linkA crack detection technique based on nonlinear acoustics is investigated in this study. Acoustic waves at a chosen frequency are generated using an actuating lead zirconate titanate (PZT) transducer, and they travel through the target structure before being received by a sensing PZT wafer. Unlike an undamaged medium, a cracked medium exhibits high acoustic nonlinearity which is manifested as harmonics in the power spectrum of the received signal. Experimental results also indicate that the harmonic components increase nonlinearly in magnitude with increasing amplitude of the input signal. The proposed technique identifies the presence of cracks by looking at the two aforementioned features: harmonics and their nonlinear relationship to the input amplitude. The effectiveness of the technique has been tested on aluminum and steel specimens. The behavior of these nonlinear features as crack propagates in the steel beam has also been studied.This research is supported by the Radiation Technology
Program under Korea Science and Engineering Foundation
(KOSEF) and the Ministry of Science and Technology
(M20703000015-07N0300-01510) and Korea Research
Foundation (D00462)
Active Sensing for Disbond Detection in FRP Strengthened RC Beams
No full textThis research was partially supported by an NSF Grant No. CMS-0529208 and Pennsylvania Infrastructure
Technology Alliance (PITA) program. The authors would like to thank the CMS Program Manager, Dr. Shi Lui
and the PITA co-director, Prof. Cristina Amon for their supports. The authors also like to thank Seung Bum Kim
and Dena E. De Luliis for assisting our experiments. The first author would like to acknowledge the Electric Power
National Scholarship Program at the Ministry of Commerce, Industry and Energy (MOCIE) in Gwachon, Korea.
The beam test was conducted by Andrew Zorn and Benjamin Reeve in the Watkins-Haggart Structural
Engineering Laboratory at the University of Pittsburgh
Application of Outlier Analysis for Baseline-Free Damage Diagnosis
No full textThis research was partially supported by an NSF Grant No. CMS-0529208 and Pennsylvania Infrastructure Technology Alliance (PITA) program. The authors would like to thank the CMS Program Manager, Dr. Shi Lui and the PITA co-director, Prof. Cristina Amon for their supports. The authors also like to thank Seung Bum Kim and Dena E. De Luliis for assisting our experiments. The first author would like to acknowledge the Electric Power National Scholarship Program at the Ministry of Commerce, Industry and Energy (MOCIE) in Gwachon, Korea. The beam test was conducted by Andrew Zorn and Benjamin Reeve in the Watkins-Haggart Structural Engineering Laboratory at the University of Pittsburgh
Active Sensing for Disbond Detection in CFRP strengthened RC beam
No full textThis research was partially supported by an NSF Grant No. CMS-0529208 and Pennsylvania Infrastructure Technology Alliance (PITA) program. The authors would like to thank the CMS Program Manager, Dr. Shi Lui and the PITA co-director, Prof. Cristina Amon for their supports. The authors also like to thank Seung Bum Kim and Dena E. De Luliis for assisting our experiments. The first author would like to acknowledge the Electric Power National Scholarship Program at the Ministry of Commerce, Industry and Energy (MOCIE) in Gwachon, South Korea. The beam test was conducted by Andrew Zorn and Benjamin Reeve in the Watkins-Haggart Structural Engineering Laboratory at the University of Pittsburgh
Debonding monitoring of CFRP strengthened RC beams without reference data nor prior decision boundaries
No full textApplication of time reversal guided waves to debond detection in CFRP strengthened RC beams
No full textDebonding monitoring of CFRP strengthened rc beams based on a time reversal process of guided waves
No full text
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