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Stretching Method-Based Operational Modal Analysis of An Old Masonry Lighthouse
Emmanouil Daskalakis1, Christos G Panagiotopoulos2, Chrysoula Tsogka3
1Vancouver Community College, 1155 E Broadway, Vancouver, BC V5T 4V5, Canada. edaskalakis@vcc.ca.
Sensors (Basel, Switzerland)
|August 22, 2019
Summary
Structural health monitoring of the Rethymnon lighthouse uses the stretching method to detect 1% frequency shifts, enabling early damage assessment. This technique shows promise for safeguarding historical monuments.
Area of Science:
- Civil Engineering
- Structural Health Monitoring
- Heritage Conservation
Background:
- Historical monuments like the Rethymnon lighthouse are susceptible to structural degradation.
- Effective monitoring is crucial for preserving cultural heritage and ensuring public safety.
Purpose of the Study:
- To evaluate the efficacy of the stretching method for structural health monitoring of the Rethymnon lighthouse.
- To assess the method's capability in detecting subtle changes in natural frequencies indicative of damage.
Main Methods:
- Utilized structural vibration data from a limited sensor network over a 3-month period.
- Applied the stretching method, comparing current structural state signals with a reference healthy condition signal.
- Defined reference quantity using an 8-day interval and current quantity using a 24-hour window.
Main Results:
- Demonstrated the ability to detect frequency shifts as small as 1% with high accuracy.
- Developed and calibrated a simple numerical model matching stretching method frequencies.
- Validated the model by comparing its simulated response during an earthquake with actual measurements.
Conclusions:
- The stretching method shows significant potential for the structural health monitoring of historical monuments.
- The study provides promising preliminary results for early damage detection and assessment.
- Further long-term monitoring with enhanced instrumentation is recommended for comprehensive analysis.
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