Analytical Modeling of Composite Molding by Resin Infusion with Flexible Tooling: VARI and RFI processes

Abstract

We present analytical modeling and closed form solutions for composite resin infusion processes such as the vacuum assisted resin infusion (VARI) process and the resin film infusion (RFI) process. As a flexible bag is placed on the top of fabric stack, while a rigid tooling is still used on the other side, a fabric deformation takes place as the resin pressure changes during the resin infiltration process. Subsequently, it is important to take into account the reinforcement compaction as well as the resin flow in the analysis of resin infusion processes. We present a fully analytical modeling of resin pressure distribution, resin flow front position, fiber volume fraction distribution, and part height change during the resin infusion process. Parametric studies are provided to investigate the influences of process parameters on the process feasibility. The evaluation of bulk permeability in the RFI process implies that the fabric compaction should be taken into account to exactly characterize the through-thickness permeability of fibrous reinforcement.