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Monitoring dynamic structural tests using image deblurring techniques

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conference contribution
posted on 24.07.2013, 08:42 by David McCarthy, Jim Chandler, Alessandro PalmeriAlessandro Palmeri
Photogrammetric techniques have demonstrated their suitability for monitoring static structural tests. Advantages include scalability, reduced cost, and three dimensional monitoring of very high numbers of points without direct contact with the test element. Commercial measuring instruments now exist which use this approach. Dynamic testing is becoming a convenient approach for long-term structural health monitoring. If image based methods could be applied to the dynamic case, then the above advantages could prove beneficial. Past work has been successful where the vibration has either large amplitude or low frequency, as even specialist imaging sensors are limited by an inherent compromise between image resolution and imaging frequency. Judgement in sensor selection is therefore critical. Monitoring of structures in real-time is possible only at a reduced resolution, and although imaging and computer processing hardware continuously improves, so the accuracy demands of researchers and engineers increase. A new approach to measuring the vibration envelope is introduced here, whereby a long-exposure photograph is used to capture a blurred image of the vibrating structure. The high resolution blurred image showing the whole vibration interval is measured with no need for high-speed imaging. Results are presented for a series of small-scale laboratory models, as well as a larger scale test, which demonstrate the flexibility of the proposed technique. Different image processing strategies are presented and compared, as well as the effects of exposure, aperture and sensitivity selection. Image processing time appears much faster, increasing suitability for real-time monitoring.

History

School

  • Architecture, Building and Civil Engineering

Citation

MCCARTHY, D.M.J., CHANDLER, J.H. and PALMERI, A., 2013. Monitoring dynamic structural tests using image deblurring techniques. IN: Basu, B. (ed.). Damage Assessment of Structures X. [Selected, peer reviewed papers from the 10th International Conference on Damage Assessment of Structures (DAMAS 2013), July 8-10, 2013, Dublin, Ireland]. Key Engineering Materials, pp.932-939.

Publisher

© Trans Tech Publications Ltd

Version

AM (Accepted Manuscript)

Publication date

2013

Notes

This conference paper was presented at the 10th International Conference on Damage Assessment of Structures (DAMAS 2013), Dublin, Ireland, July 8th-10th 2013.

ISBN

9783037857960

ISSN

1013-9826

eISSN

1662-9795

Language

en