Study on the monitoring of resin flow and curing in the vacuum assisted resin transfer molding process using a long-period fiber Bragg grating

The long-period fiber grating (LPG) has received considerable attention in various fiber-optic sensor implementations. In this study, we apply LPG for estimation of the resin flow and transformation in vacuum assisted resin transfer molding (VARTM). An LPG is inserted into the glass mat to monitor the transmission spectrum with an optical spectrum analyzer. The curing reactions in VARTM are also observed using the same method. From the results, it is shown that the proposed LPG sensor can be effectively used in monitoring the curing reaction in VARTM.