Coatings, either soft or hard, are commonly used to protect steel against corrosion for longer service life. With coatings, assessing the corrosion behavior and status of the substrate is challenging without destructive analysis. In this paper, fiber Bragg (FBG) grating sensors were proposed to nondestructively evaluate the corrosion behavior of steel coated with two popular coatings, including the polymeric and wire arc sprayed Al-Zn coating. Laboratory accelerated corrosion tests demonstrated that the embedded FBG sensors inside both the soft and hard coatings can effectively quantify the corrosion rate, monitor the corrosion progress, and detect the coating damages and crack propagation of coated steel in real time. The laboratory electrochemical corrosion test on the wire arc sprayed Al-Zn coating validated the proposed embedded FBG sensor method with a good agreement in comparison. The proposed sensing platform provides an alternative nondestructive real-time corrosion assessment approach for coated steel in the field.
Corrosion Localization of Steel Structures Using Fiber Bragg Grating Sensors
Steel, which has high tension and compression strength, is a widely used civil engineering material in constructing building, bridge, pipelines, and other structures. However, steel has a well-known weakness, which is suspected to corrosion. Steel corrosion would significantly impact the reliability and safety of steel structures. Accurately locating and assessing the corrosion of steel structures would contribute to timely maintenance and thus, extend the service life of the steel structures. Although advances have been made to use nondestructive evaluation (NDE) technologies to locate and assess corrosion on steel structures, due to the lack of labor and budget for frequent NDE assessment on steel structures, remote and real-time approaches to locate and assess corrosion are still in great needs. Fiber optic sensors, especially, fiber Bragg gating (FBG) sensors, with unique advantages of real-time sensing, compactness, immune to EMI and moisture, capability of quasi-distributed sensing, and long life cycle, will be a perfect candidate for long-term corrosion assessment. However, due to the fact that FBG is a localized sensor, it is very challenging to locate corrosion using FBG sensors. In this study, algorithms are developed to locate corrosion on steel structures using FBG sensors. Detail sensing principle, localization algorithm development and calibration more »
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- Proceedings 9th International Conference on Structural Health Monitoring of Intelligent Infrastructure
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- National Science Foundation
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