A large-area electronics (LAE) strain sensor, termed soft elastomeric capacitor (SEC), has shown great promise in fatigue crack monitoring. The SEC is capable to monitor strain changes over a large structural surface and undergo large deformations under cracking. Previous tests verified that the SEC can detect and localize fatigue cracks under low-cycle fatigue loading. In this paper, we further investigate the SEC's capability for monitoring high-cycle fatigue cracks, which are commonly seen in steel bridges. The peak-to-peak amplitude (pk-pk amplitude) of the SEC measurement is proposed as an indicator of crack growth. This technique is is robust and insensitive to long-term capacitance drift. To overcome the difficulty of identifying the pk-pk amplitude in time series due to high signal-to-noise ratio, a signal processing method is established. This method converts the measured SEC capacitance and applied load to power spectral densities (PSD) in the frequency domain, such that the pk-pk amplitudes of the measurements can be accurately extracted. Finally, the performance of this method is validated using a fatigue test of a compact steel specimen equipped with a SEC. Results show that the crack growth under high-cycle fatigue loading can be successfully monitored using the proposed signal processing method.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/625834 |
| Date | 12 April 2017 |
| Creators | Kong, Xiangxiong, Li, Jian, Collins, William, Bennett, Caroline, Laflamme, Simon, Jo, Hongki |
| Contributors | Univ Arizona, Dept Civil Engn & Engn Mech, The Univ. of Kansas (United States), The Univ. of Kansas (United States), The Univ. of Kansas (United States), The Univ. of Kansas (United States), Iowa State Univ. (United States), The Univ. of Arizona (United States) |
| Publisher | SPIE-INT SOC OPTICAL ENGINEERING |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | Article |
| Rights | © (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). |
| Relation | http://proceedings.spiedigitallibrary.org/proceeding.aspx?doi=10.1117/12.2260364 |
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