Modeling capillary pressure in dual-scale fibrous structures for resin transfer molding processing of composites: A brief review and perspective

Abstract

Resin transfer molding has garnered significant attention for the development of high performance and complex structural composites. Capillary forces, driven by surface tension and fibre wettability, play a crucial role in the impregnation of fibres by resin flow. Capillary pressure is identified as a key factor in void formation and transport during the molding process. The influence of geometrical parameters on the capillary pressure is also examined. This review delves into the mechanism of capillary pressure, considering the effects of fibre arrangement and dual-scale pore structures during the resin transfer molding filling stage. The models incorporate fluid dynamics, surface tension and fibre wettability, and is validated by the wicking experiments. The recent works suggest that better control over capillary pressure during resin transfer molding processing can lead to improved filling uniformity, reduced void content, and enhanced mechanical properties of composite materials. The development of artificial intelligence assisted methods for capillary pressure assessment and control shows great potential for improving high-performance composite manufacturing.