Abstract
To analyze the long‐term monitoring reliability and life expectancy of FBG‐based steel strands, accelerated corrosion and tensile tests were carried out and a life‐prediction model was constructed. The validation test results indicated that the monitoring strain sensitivity of FBG‐based steel strands decreases with an increase in solution concentration and time in a corrosive acidic environment. When the sensitivity dropped to about 80% of its initial value, the FBG sensor suddenly failed. The life‐prediction model indicates that the predicted monitoring life of an FBG sensor is about 56 years in an unstressed condition but about 27 years under the stressful conditions that FBG‐based steel strands are subjected to in their working environment. So, to improve their monitoring reliability and monitoring life, it is suggested that FBG‐based steel strands might be prepared by “pre‐loading.”
Highlights
Steel strands are a core component of many engineering structures, including bridge cables, hanger rods, geotechnical anchor cables, and internal and external prestressed components. ey operate in conditions where “a slight move in one part may affect the situation as a whole.” So, under the combined action of stress and environmental corrosion, the mechanical performance of steel strands slowly degenerates over time and they may even fail
The warping of the bonding layer gradually expanded from the boundary to the bottom of groove and the warped part became soft. e black spots on the surface of the central wire became deeper in color and larger in size, gradually transforming into speckles of rust. e warping outwards of the bonding layer boundary and the appearance of the black spots on the surface of the central wire sped up the failure of the fiber Bragg grating (FBG)
Εg and εm represent the strain in the FBG sensor and the matrix, respectively; L represents half the adhesive length of the optical fiber sensor; Gp and Eg represent the shear elastic modulus of the bonding layer and Young’s modulus of the fiber, respectively; and rm and rg represent the outer diameter of the bonding layer and the outer diameter of the optical fiber, respectively
Summary
Steel strands are a core component of many engineering structures, including bridge cables, hanger rods, geotechnical anchor cables, and internal and external prestressed components. ey operate in conditions where “a slight move in one part may affect the situation as a whole.” So, under the combined action of stress and environmental corrosion, the mechanical performance of steel strands slowly degenerates over time and they may even fail. The real-time monitoring of stress in steel strands plays an important role in the safety management of engineering structures. The monitoring techniques for stress in steel strands include elastomagnetic sensors [1, 2], electrical strain gauges [3], piezoelectric transducer actuator [4], and so on. These types of electromechanical sensors are subjected to long-term risk as well as suffering from noise during long distance transmission and electromagnetic interference. Fiber Bragg grating (FBG) sensors use light as their sensing medium [5]. ey exhibit stable sensing characteristics and high accuracy and possess anti-electromagnetic interference capabilities [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callSimilar Papers
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
