Experimental study on three-point bending performance of CFRP shaft embedded FBG sensor

Abstract

The bending deformation of Carbon Fiber Reinforced Polymer (CFRP) shaft is one of the important indicators reflecting its performance. Monitoring the deformation of CFRP shaft under different loads is of great significance for the optimal design of CFRP shaft. Fiber Bragg Grating (FBG) sensor is small in diameter, easy to be embedded inside the CFRP shaft, which has little influence on the structure itself. In addition, it can realize "one fiber multi-point" measurement, which is very suitable for the internal monitoring of anisotropy composites. This paper proposes a pre-embedded FBG sensor to monitor CFRP shaft strain. Prepared CFRP shaft test piece. Four FBG sensors are embedded inside the shaft, and four FBG sensors and four strain gauges are pasted on the surface of the shaft. The CFRP shaft was subjected to three-point bending loading on a universal testing machine. The strain data obtained by FBG sensor and strain gauge under various loads were compared and analyzed. The feasibility and accuracy of the embedded FBG sensor to monitor CFRP shaft strain were verified.