Analysis of the post-filling phase of the vacuum-assisted resin transfer molding process

Abstract

The vacuum-assisted resin transfer molding process uses a compliant vacuum bagging material which allows the thickness of the saturated preform to change as a function of pressure. The final thickness of the part is dependent on the post-filling phase where excess resin is bled from the preform to achieve a desired final part thickness. The flow of resin during the bleeding process is dependent on the compaction and permeability characteristics of the preform material. This paper examines the post-filling stage of the vacuum-assisted resin transfer molding process through finite element-based flow simulation and experimental studies. The studies focus on thick laminates where both in-plane and through thickness flows are considered. Comparisons of experimental and simulation results for two different post-filling scenarios provide insight into the post-filling phase of the vacuum-assisted resin transfer molding process including model validation as well as understanding of limitations of compaction/relaxation constitutive models in predicting final preform thickness.