Two sorts of fiber optic sensor monitoring the cure process of composite laminate

Two new sorts of fiber optic sensor are designed. Firstly, the variation of refractive index of resin surrounding the embedded fiber optic was mean to observed by measuring the speckle spatial spectrum at the end-face of the fiber optic. Secondly, it is proposed to measuring the change of thickness of the laminate by using fiber optic microbend attenuation. The experiment results measured by the fiber optic sensors are given. The first sort of sensor was found to be able to detect the viscosity process of the resin matrix during cure process including the minimum point of viscosity, the gelation point and the end point of cure process; the second sort of sensor could detect the course of change of the thickness of composite laminate pressed by operation pressure. It is benefit for us to optimize the operation technology and to establish the intelligent monitoring system about curing process of composites for the reason that the viscosity process and the change course of the thickness of laminate can be monitored.