Integrated flow and stress modeling for infusion and curing process in liquid composite molding

Liquid composite molding, such as resin transfer molding and vacuum-assisted resin transfer molding, is an economical composite manufacturing technique for largescale parts. Modeling of the flow phenomena during the infusion process and the stress build-up in the subsequent curing process is imperative to improve part quality and reduce the number of trial tests. Despite the abundance of literature in both flow and stress modeling, an integrated model that couples the flow and stress physics is lacking. In this work, we combined the state-of-the-art flow and stress models to establish such an integrated framework. An infusion flow model is developed with the commercial computational fluid dynamics software STAR-CCM+, which incorporates the submodels to account for flow front evolution, compaction, and resin reaction. Several stress-based models are implemented in ABAQUS to account for fabric draping, compaction, and curing-induced thermal and chemical deformation. To demonstrate the importance of modeling the coupled physics, we conducted three case studies to show (1) effects of draping on the flow front evolution, (2) effects of degree of cure advection during infusion on the curing-induced stress build-up, and (3) effects of flowcompaction coupling on the flow front and dry spot formation in vacuum infusion.