Fig. 1. Structure of the FBG sensor

Fig. 2. Packaging process of trifarious FBG strain sensor. (a) Welding schematic diagram; (b) photo after encapsulation; (c) photo after calibration

Fig. 3. Calibration of the sensor

Fig. 4. Schematic diagram of the experimental setup

Fig. 5. Static test curves of the two sensors. (a) Time domain signal of resistance strain gauge; (b) time domain signal of FBG strain sensor

Fig. 6. Sinusoidal sweep response curves of two sensors. (a) Time domain signal of strain gauge; (b) time domain signal of FBG strain sensor

Fig. 7. Random vibration time domain signals of two sensors. (a) Time domain signal of strain gauge; (b) time domain signal of FBG strain sensor

Fig. 8. Power spectrum of random vibration signals of two sensors. (a) Strain gauge; (b) FBG strain sensor