PSI - Issue 64

Mingyang Xi et al. / Procedia Structural Integrity 64 (2024) 515–522

520

6

Mingyang Xi et al. / Structural Integrity Procedia 00 (2024) 000 – 000

Fig. 7. Self-sensing Strand Layout Diagram

3.2. Field Application The construction process of the self-sensing strands mentioned in this article, compared to traditional strands, includes two key additional steps: data measurement and line protection. The construction process mainly comprises preparation for construction, threading, initial value measurement, etc., as detailed in Fig. 8. This process ensures the correct installation of the self-sensing strands and the effective performance of their functions. In terms of monitoring technology, by embedding a 0.1mm diameter fiber optic sensor on the surface of the central wire of the strand and coupling it, an integrated smart material with both load-bearing and sensory perception functionalities is created. Each self-sensing strand undergoes strict data calibration before leaving the factory, ensuring the accuracy and reliability of the monitoring data.

Fig. 8. Self-sensing Strand Construction Process Diagram Before the tensioning of self-sensing strands on-site, it's essential first to determine the initial values of the fiber Bragg gratings within the strands. Once the initial values are confirmed, the prestressing work of the self-sensing strands can be completed. During this period, the wavelength changes of the fiber Bragg grating sensors are continuously monitored. Due to the impact of on-site construction, 1 out of the planned 5 self-sensing strands was not used in construction, while the remaining 4 recorded the full course of wavelength changes. After tensioning, excess strands are cut off, and the fiber optic jumpers are protected (Fig. 9.). Continuous monitoring of the prestress in the self-sensing strands is carried out for 24 hours (for specific monitoring data, see Table 3-1), followed by anchor sealing and grouting.