Monitoring of the carbon fiber wound composites curing process based on FBG sensors

Abstract

To study the strain and temperature distribution during the carbon fiber wound composite curing process, the fiber Bragg grating (FBG) sensors were used to monitor the temperature and strain distribution of the carbon fiber composite ring specimen during the curing process. The results show that the FBG sensors can effectively monitor the strain and temperature distribution inside the ring specimen during the curing process. The trends of temperature changes at different thickness are similar. However, there is an obvious temperature gradient and the temperature difference between the surface layer and the inner layer is up to 6.2°C. In the stage of heating and heat preservation, the inner strain of the ring specimen near the mould during the curing process is positive, and the strain change outside the specimen is always negative. During the natural cooling stage, the internal strains of the specimen changed greatly. After the curing, the inner and outer layers show the shrinkage strain of different values. This indicates that there is an uneven cure residual stress in the cured ring specimen.