Reference-free fatigue crack detection using nonlinear ultrasonic modulation under various temperature and loading conditions
| Autor: | Hoon Sohn, Martin P. DeSimio, Hyung Jin Lim, Kevin Brown |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Materials science
Mechanical Engineering Acoustics Aerospace Engineering Low frequency Lead zirconate titanate Computer Science Applications chemistry.chemical_compound Nonlinear system Transducer chemistry Control and Systems Engineering Composite plate Signal Processing Electronic engineering Demodulation Ultrasonic sensor Continuous wavelet transform Civil and Structural Engineering |
| Zdroj: | Mechanical Systems and Signal Processing. 45:468-478 |
| ISSN: | 0888-3270 |
| Popis: | This study presents a reference-free fatigue crack detection technique using nonlinear ultrasonic modulation. When low frequency (LF) and high frequency (HF) inputs generated by two surface-mounted lead zirconate titanate (PZT) transducers are applied to a structure, the presence of a fatigue crack can provide a mechanism for nonlinear ultrasonic modulation and create spectral sidebands around the frequency of the HF signal. The crack-induced spectral sidebands are isolated using a combination of linear response subtraction (LRS), synchronous demodulation (SD) and continuous wavelet transform (CWT) filtering. Then, a sequential outlier analysis is performed on the extracted sidebands to identify the crack presence without referring any baseline data obtained from the intact condition of the structure. Finally, the robustness of the proposed technique is demonstrated using actual test data obtained from simple aluminum plate and complex aircraft fitting-lug specimens under varying temperature and loading variations. |
| Databáze: | OpenAIRE |
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