UV stepwise cured fabrication of glass fiber/acrylate composites: Effects of exposure dose on curing uniformity and interlaminar shear strength

To determine the quality of composites cured with UV light ply by ply, the effects of exposure dose on the cure uniformity and interlaminar shear strength of composite laminates were investigated. This was done by using UV power meter, differential scanning calorimetry, and the fiber optic strain sensors. According to differential photocalorimety results, the accumulative curing effect is remarkable in the stepwise UV-curing process, which results in gradual improvement of the degree of cure of the underlying ply. The cure uniformity increased with increasing exposure dose, but higher exposure dose led to a decrease of the interlaminar shear strength. This was due to increased shrinking strain and residual stress according to the results from the fiber optic strain sensors.