Date of Publication :11th September 2023

Abstract: Vacuum infusion technologies are mainly used in the production of lightly loaded composite structures due to the relatively small and unevenly distributed of the fiber volume fraction and a significant variation in the wall thickness of finished parts, which is due to a significant internal pressure gradient in the preform upon completion of the infusion process. Some works have proposed and experimentally substantiated the application of controlled external pressure to the surface of the preform with a gradual increase in pressure in the vacuum vent and removal of excess resin. It has been established that the efficiency of the process depends on the duration, rate and maximum value of the applied pressure. This article presents a computer model of such a post-infusion process, supplementing the previously developed model of vacuum infusion, the simulation results of which are the initial conditions for the model presented below. The model is a finite element implementation of the coupled problem including Darcy's law, continuity and compressibility equations for a curable liquid resin and a compressed porous medium. The results of the process simulation give the distribution of pressure, porosity, wall thickness of the part during and after changes in controlled pressures, allowing you to achieve the best possible quality objectives for given resin and preform properties.

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