A distributed self-sensing FRP anchor rod with built-in optical fiber sensor

The difficulties induced from large-scale measurement and sensor installation make it a big challenge but an urgent need to predict the mechanical behavior of fiber reinforced polymer (FRP) anchor rod passing through the complicated areas under harsh environments. In an effort to solve this challenge, this paper proposes a novel distributed self-sensing FRP anchor rod with built-in optical fiber sensor. For the purpose of self-sensing, the technique of Brillouin Optical Time Domain Analysis (BOTDA) is applied to the built-in optical sensor for measuring the full-scale strain of the rod. Demonstration tests taking into account the de-bonded damage were carried out to simulate the field cases. A self-sensing FRP anchor rod was embedded in a 12-m-long sand slot and pulled from one end. The full-scale strain was measured utilizing the BOTDA interrogator. Using this collected data, the integrity displacement of the rod was also investigated associated with its interfacial damage evolution.

► We propose a distributed self-sensing FRP anchor rod with built-in optical fiber sensor.
► It effectively monitors itself full-scale strain evolution using BOTDA technique.
► It further provides damage evolution associated with the integrity displacement.
► It may provide an effective approach for behavior monitoring of FRP anchor rod.