Optimization method to reduce three-dimensional thermal gradients in resin transfer molding

Presently, the mold and resin are heated to promote resin flow and shorten curing period in order to improve manufacturing efficiency of resin transfer molding (RTM). This nonisothermal manufacturing process easily generates three-dimensional thermal gradients in the direction of resin flow and thickness of composite part. However, the existing heating systems only consider the thermal gradients along thickness direction. The thermal gradients in direction of resin flow cannot be reduced which will lead to residual stress even deformation and cracking in composite part. This article aims at reducing the three-dimensional thermal gradients in the direction of resin flow and thickness of composite part. Based on the theory of energy and fluid flow, an optimization method of heating system design by using numerical simulation is proposed. The results show this method reduces the three-dimensional thermal gradients effectively in composite part manufactured by RTM process. This study can provide powerful tools for heating system design to manufacture composites products in polymer industry. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48948.