Modeling and simulation of voids and saturation in liquid composite molding processes

Abstract

We propose modeling and simulation of the void formation and the tow saturation in liquid composite molding processes. The present model addresses the void formations in the macropore between fiber tows as well as in the micropore inside fiber tows. We also consider the bubble compression and tow saturation after voids are formed at the flow front. Finally, a void migration model is considered. The present models are validated by a comparison between simulation results and experimental data. The simulation results successfully represent important features of the void physics: the correlation of void formation at the flow front with capillary number, the advantage of vacuum application at air vents to reduce the void content inside tows, and the existence of partially saturated zone behind the global flow front. The representation of mold filling patterns by a degree of saturation shows the presence of a bubbly zone behind the flow front.