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Abstract
This paper describes a global non-destructive testing technique for detecting fatigue cracking in engineering components. The technique measures the mixing of two ultrasonic sinusoidal waves which are excited by a small piezoceramic disc bonded to the test structure. This input signal excites very high-order modes of vibration of the test structure within the ultrasonic frequency range. The response of the structure is measured by a second piezoceramic disc and the received waveform is analysed using the bispectrum signal processing technique. Frequency mixing occurs as a result of nonlinearities within the test structure and fatigue cracking is shown to produce a strong mixing effect. The bispectrum is shown to be particularly suitable for this application due to its known insensitivity to noise. Experimental results on steel beams are used to show that fatigue cracks, corresponding to a reduction in the beam section of 8%, can be detected. It is also shown that the bispectrum can be used to quantify the extent of the cracking. A simple nonlinear spring model is used to interpret the results and demonstrate the robustness of the bispectrum for this application.
Original language | English |
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Pages (from-to) | 1515-1530 |
Number of pages | 16 |
Journal | Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences |
Volume | 462 |
Issue number | 2069 |
DOIs | |
Publication status | Published - 21 Dec 2006 |
Keywords
- Bispectral analysis
- Fatigue crack
- Nonlinear
- Structural health monitoring
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Dive into the research topics of 'Global crack detection using bispectral analysis'. Together they form a unique fingerprint.Projects
- 1 Finished
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THE ULTRASONIC DETECTABILITY AND SIZING OF ROUGH, PARTIALLY CLOSED CRACKS IN REAL STRUCTURES
Drinkwater, B. W. (Principal Investigator)
1/01/03 → 1/10/06
Project: Research