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Comparison of Experimentally Determined Two-Dimensional Strain Fields and Mapped Ultrasonic Data Processed by Coda
Felix Clauß1, Niklas Epple2, Mark Alexander Ahrens1
1Lehrstuhl für Massivbau, Fakultät für Bau- und Umweltingenieurwissenschaften, Ruhr-Universität Bochum, Universitätstraße 150, 44801 Bochum, Germany.
Sensors (Basel, Switzerland)
|July 24, 2020
Summary
Ultrasonic waves can detect structural changes in concrete, but quantitative strain correlation needs more research. This study used Coda Wave Interferometry to analyze ultrasonic signals during bending tests.
Area of Science:
- Structural Health Monitoring
- Materials Science
- Non-Destructive Testing
Background:
- Ultrasonic waves are sensitive to structural alterations like strain, humidity, and temperature.
- Coda waves, in particular, offer high sensitivity for examining entire structures using transducer networks.
Purpose of the Study:
- To investigate the influence of mechanical strain on ultrasonic signals in reinforced concrete.
- To assess the viability of ultrasonic wave measurements as a reference for inferring structural changes.
Main Methods:
- A four-point bending test was performed on a reinforced concrete beam.
- Ultrasonic signals from transducer pairings were correlated with strain fields using Coda Wave Interferometry.
- Analysis included non-cracked and cracked states with varying crack depths.
Main Results:
- Relative Velocity Changes in Attribute Maps qualitatively distinguished compression and tension zones.
- The study identified relative changes in ultrasonic signals across the beam's height.
- Quantitative assertions regarding the correlation between ultrasonic and strain results were not achieved due to methodological limitations.
Conclusions:
- Ultrasonic wave analysis can qualitatively identify strain-induced changes in concrete structures.
- Further research is needed to establish quantitative correlations between ultrasonic measurements and strain for both intact and cracked concrete.
- Methodological refinements are required for accurate, quantitative structural health monitoring using ultrasonic waves.
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