Smart sensors for monitoring crack growth under fatigue loading conditions
Autor: | Buli Xu, Victor Giurgiutiu, Yuh Chao, Rishi Gaddam, Shu Liu |
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Rok vydání: | 2006 |
Předmět: |
Materials science
business.industry Acoustics Structural engineering Piezoelectricity 500 kHz Computer Science Applications Lamb waves Transmission (telecommunications) Control and Systems Engineering mental disorders Fatigue loading Waveform Structural health monitoring Electrical and Electronic Engineering business Electrical impedance |
Zdroj: | Smart Structures and Systems. 2:101-113 |
ISSN: | 1738-1584 |
DOI: | 10.12989/sss.2006.2.2.101 |
Popis: | Structural health monitoring results obtained with the electro-mechanical (E/M) impedance techniqueand Lamb wave transmission methods during fatigue crack propagation of an Arcan specimen instrumented with piezoelectric wafer active sensors (PWAS) are presented. The specimen was subjected in mixed-mode fatigue loading and a crack was propagated in stages. At each stage, an image of the crack and the location of the crack tip were recorded and the PWAS readings were taken. Hence, the crack-growth in the specimen could be correlated with the PWAS readings. The E/M impedance signature was recorded in the 100 - 500 kHz frequency range. The Lamb-wave transmission method used the pitch-catch approach with a 3-count sine tone burst of 474 kHz transmitted and received between various PWAS pairs. Fatigue loading was applied to initiate and propagate the crack damage of controlled magnitude. As damage progressed, the E/M impedance signatures and the waveforms received by receivers were recorded at predetermined intervals and compared. Data analysis indicated that both the E/M impedance signatures and the Lamb-wave transmission signatures are modified by the crack progression. Damage index values were observed to increase as the crack damage increases. These experiments demonstrated that the use of PWAS in conjunction with the E/M impedance and the Lamb-wave transmission is a potentially powerful tool for crack damage detection and monitoring in structural elements. |
Databáze: | OpenAIRE |
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