In‐plane permeability determination for simulation of liquid composite molding of complex shapes

Abstract Process simulation forms an important part of the design loop for parts manufactured by liquid composite molding. Critical to this is the determination of accurate permeability data. While constitutive models and test methods for determination of in‐plane permeability of mats and fabrics exist, these do not take account of the effects of changes in fiber architecture during preform manufacture. The deformation behavior of mats and fabrics is reviewed, leading to fiber architecture predictions based upon deformed geometry. Existing models are applied to estimate the distribution of in‐plane permeabilities within the preform based upon the predicted fiber architecture. The predictions are compared with test results for pre‐stretched and pre‐sheared reinforcements, and the method is demonstrated for two prototype automotive parts.