Vibration measurement of compressor blades with fiber Bragg grating

We reported the vibration measurement of compressor blades by using fiber Bragg gratings. The low order vibration modes were focused on and the corresponding distributions of FBGs were designed. The arrangement position of the fiber Bragg grating sensor was determined by analyzing the strain distribution of the blade model in the low order mode. It was verified by experiments that the sensor can identify the lower vibration modes of the blade. The experimental results were consistent with the finite element based simulation in terms of eigen frequency and the signal intensity regularity of the sensor at every eigen frequency was consistent with the strain distribution of each sensor under the simulation results. The bending torsional vibration of the blade was identified according to the response of each sensor at the respective eigen frequency. In this paper, fiber Bragg grating (FBG) sensors were arranged on the blade to achieve low modal detection of blade, which laid the foundation for high-order modal detection and high frequency ultrasonic detection of blade.