Permeability analysis of non-crimp fabrics for resin transfer molding

Resin transfer molding (RTM) is one of the most common processes for producing fiber-reinforced polymer composites. Permeability tensor of the fiber preform is a key material property for satisfactory RTM process. Therefore, it is necessary to acquire a precise permeability tensor from simulation and experiment. In this study, the creeping flow simulation was carried out to obtain the flow field in a unit cell, and Darcy’s law was utilized to compute the permeability tensor. The unit cell for the non-crimp fabrics was defined and constructed, and the permeability was analyzed in the axial, transverse, and thickness directions. The effect of shifted preform layers was also evaluated for more realistic permeability tensor. The predicted and measured results were compared with respect to the fiber volume fraction, fabric pattern, and stacking structure.