Manufacture and characterization of carbon fiber composite stiffened skin by resin film infusion/prepreg co-curing process

I-shaped stiffened skin was manufactured by a new co-cured resin film infusion process (co-RFI) with fiber preform stiffener and prepreg skin. One kind of epoxy resin film and four kinds of carbon fiber prepreg were used. Resin flow behavior, processing quality, and mechanical performance were investigated for co-RFI stiffened skin. Sole prepreg/autoclave process and resin film infusion process were also adopted for comparison. Resin flow front and resin pressure were detected by self-developed monitoring systems. Optical micrographs and thickness measurement were employed to evaluate processing quality. Moreover, pull-off test was used to analyze the influences of core filler and prepreg systems in skin on the mechanical performance of stiffened skin. The results show that with reasonable processing conditions, good processing quality, and mechanical property at co-curing interface region can be achieved for co-RFI stiffened skin. Co-RFI process is suitable to fabricate composite structure with high flexibility in materials and structures.