Fiber Bragg grating and etched optic sensors for flow and cure monitoring of resin transfer molded composite structures

In this study, we present the research conducted on in situ process monitoring (cure and flow) of resin transfer molded glass fiber reinforced polymer composites using fiber Bragg grating (FBG), and etched bare fiber optic sensors. Both FBG and etched fiber sensors are embedded into glass fiber reinforced composites manufactured by the Resin Transfer Molding (RTM) method, and are used to monitor the flow front during the resin injection process and subsequently the cure cycle. The results of this study have shown that both the FBG and etched sensors can be used efficiently for flow and cure monitoring in the RTM process. The experimental results of etched sensors are in accordance with those of FBG sensors for cure monitoring.