A dual‐scale analysis of macroscopic resin flow in vacuum assisted resin transfer molding

Abstract In Vacuum Assisted Resin Transfer Molding (VARTM) where a sacrificial medium is used to facilitate the resin flow, the velocity of the resin varies drastically between inside the sacrificial medium and inside the fiber preform. Although the thickness‐to‐length ratio of a VARTM product is usually small, a 3‐D analysis is required for analyzing the lead‐lag flow in the two different media. The problem associated with the full 3‐D analysis is the CPU time. A full 3‐D numerical mesh comprising a large number of nodes requires a CPU time impractical on most computer platforms. In this study, a dual‐scale analysis technique was proposed. First, the flow analysis for the entire calculation domain was conducted in 2.5‐D. Using the results of the 2.5‐D calculation, the 3‐D analysis was performed for a small area of special concern. In some numerical examples, the local 3‐D analysis could discover an eccentric flow pattern as well as the lead‐lag flow that would inevitably be neglected in 2.5‐D simulations. The global‐local analysis technique practiced in this study can be used to analyze the intricate flow of resin through non‐uniform media in affordable CPU times. Polym. Compos. 25:510–520, 2004. © 2004 Society of Plastics Engineers.