Strain Transfer of Fiber Bragg Grating Sensor Externally Bonded to FRP Strip for Structural Monitoring after Reinforcement

To date, a method of attaching a FRP (fiber-reinforced polymer) to concrete members with epoxy has been widely applied to increase the strength of the member. However, there are cases in which the adhesion of the epoxy deteriorates over time and the reinforcing effect of the FRP is gradually lost. Therefore, monitoring whether or not the reinforcing effect is properly maintained is needed in order to prevent a decrease in the structural performance of the member improved by FRP reinforcement. In this regard, this study examines FRP with OF (optical fiber) sensors to monitor the reinforcing effect of FRP in concrete structural members. In particular, this paper seeks to determine an appropriate adhesion length when FBG (fiber Bragg grating) based OF sensors are externally bonded to FRP strips with epoxy resin. To this end, a tensile test was carried out to evaluate the sensing performance according to the adhesion length. In addition, an analytical approach was performed and the result were compared with test result. The results of the experimental and analytical studies showed that the strain generated in the FRP is sufficiently transferred to the OF if the total adhesion length of it is 40 mm or more in consideration of the error in the epoxy thickness.

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Insight into the nondestructive performance evaluation of fiber‐reinforced polymer composite laminate immersed in produced water using embedded fiber Bragg grating sensor

Polymer Composites ◽

10.1002/pc.26181 ◽

2021 ◽

Author(s):

Santoshi Mohanta ◽

Yashwanth Padarthi ◽

Jeetendra Gupta ◽

Swati Neogi

Keyword(s):

Performance Evaluation ◽

Fiber Bragg Grating ◽

Polymer Composite ◽

Composite Laminate ◽

Produced Water ◽

Fiber Reinforced Polymer ◽

Bragg Grating ◽

Reinforced Polymer ◽

Bragg Grating Sensor ◽

Insight Into

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Investigation of the Curing Residual Stress in Gr/Epoxy Laminated Composites by Using Embedded Fiber Bragg Grating Sensor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.357 ◽

2011 ◽

Vol 287-290 ◽

pp. 357-363

Author(s):

Chia Chin Chiang

Keyword(s):

Residual Stress ◽

Fiber Bragg Grating ◽

Stress Measurement ◽

Polymeric Composite ◽

Bragg Grating ◽

Curing Process ◽

Fiber Sensors ◽

Application Potential ◽

Bragg Grating Sensor

The curing monitoring of the polymeric composite materials has attracted wide interests recently. In order to improve the performance of Gr/Epoxy composites, monitoring the curing process is a demand, especially for the characterization of residual stress after manufacture. The main objective of current research is to explore the application potential of embedded fiber Bragg grating (FBG) to monitor the characterization of the curing process in a Graphite/Epoxy composite. The changes in the shape of the optical spectra, intensity attenuation as well as wavelength shifts in the optical fiber sensors were utilized to assess the curing development and residual stress measurement. The residual stress yielding during curing process was analyzed and presented systematically in this paper.

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