Accurate Liquid Resin Infusion simulation through a Fluid-Solid coupled approach

The production rates increase in aerospace industry implies a growing interest in composite manufacturing process simulation with a strong requirement on predictive accuracy. In this context, ESI enhances its PAM-COMPOSITES software introducing fluid-solid coupled approach in PAM-RTM module in order to simulate more accurately Liquid Resin Infusion 

(LRI) process. LRI consists in impregnating a dry preform placed onto a rigid half-mold and under  distribution medium and a vacuum bag. During the impregnation resin flows preferentially into the distribution medium and then in the preform which may undergo deformations due to the flexibility of the vacuum bag. 

Usual 2.5D approaches, using shell elements with thickness depending on resin pressure, cannot account for resin flow pattern through the thickness due to permeability and fiber fraction gradients implied by the material used and/or solid mechanics effects (such as compression in curvatures).

ESI new approach, resulting from several years of collaboration with academics, consists in a 3D finite element modeling. It is based on the coupling of resin flow, governed by Darcy’s law, with the preform behavior, considered as porous medium undergoing deformations, through Terzaghi’s principle. Thus it results in more predictive filling time and properties (thicknesses, fiber volume contents, geometry) of the final product.