A method for compensation of the temperature effect disturbing Lamb waves propagation. Ambroziński, L., Magda, P., Stepinski, T., Uhl, T., & Dragan, K. In AIP Conference Proceedings, volume 1581 33, 2014.
doi  abstract   bibtex   
Variations of environmental conditions, such as temperature, affect propagation of Lamb waves, which can severely limit their use for damage detection in SHM systems. Two approaches can be used to handle this effect in order to improve robustness of SHM systems, optimal baseline selection (OBS) and baseline signal stretch (BSS). The OBS techniques require collection of signals and considerable amount of memory for data storage. Here, we present a novel technique which can be classified as a BSS approach. The proposed technique requires a single baseline only for compensation of temperature influence on Lamb waves' snapshots. The proposed scheme consists of two steps: first, the instantaneous phase of the snapshot is estimated and it is aligned with that of the baseline in the second step. Since the snapshots are generally nonstationary due to medium dispersion, wavelet transform is used for the estimation of their instantaneous phase. After phase alignment the waveform is stretched and the temperature influence is compensated. The phase-compensated snapshots can be subsequently analyzed using classical damage indices which results in damage indices insensitive to temperature variation. \textcopyright 2014 AIP Publishing LLC.
@inproceedings{Ambrozinski2014a,
	Abstract = {Variations of environmental conditions, such as temperature, affect propagation of Lamb waves, which can severely limit their use for damage detection in SHM systems. Two approaches can be used to handle this effect in order to improve robustness of SHM systems, optimal baseline selection (OBS) and baseline signal stretch (BSS). The OBS techniques require collection of signals and considerable amount of memory for data storage. Here, we present a novel technique which can be classified as a BSS approach. The proposed technique requires a single baseline only for compensation of temperature influence on Lamb waves' snapshots. The proposed scheme consists of two steps: first, the instantaneous phase of the snapshot is estimated and it is aligned with that of the baseline in the second step. Since the snapshots are generally nonstationary due to medium dispersion, wavelet transform is used for the estimation of their instantaneous phase. After phase alignment the waveform is stretched and the temperature influence is compensated. The phase-compensated snapshots can be subsequently analyzed using classical damage indices which results in damage indices insensitive to temperature variation. {\textcopyright} 2014 AIP Publishing LLC.},
	Author = {Ambrozi{\'{n}}ski, L. and Magda, P. and Stepinski, T. and Uhl, T. and Dragan, K.},
	Booktitle = {AIP Conference Proceedings},
	Doi = {10.1063/1.4864951},
	Isbn = {9780735412118},
	Issn = {15517616 0094243X},
	Keywords = {[Instantaneous Phase, Lamb waves, SHM, Temperature},
	Title = {{A method for compensation of the temperature effect disturbing Lamb waves propagation}},
	Volume = {1581 33},
	Year = {2014},
	Bdsk-Url-1 = {http://dx.doi.org/10.1063/1.4864951}}

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