A mesoscopic model for coupled drape-infusion simulation of biaxial Non-Crimp Fabric

Modelling fabric draping can be performed using simplified mapping or more detailed finite element methods that allow greater accuracy and features such as tooling, blankholders and friction to be included. The materials laws, however, invariably treat the fabric as a homogenized continuum in which stretch, shear and bending stiffness are calibrated against coupon fabric tests. Certain fabrics such as stitched Non-Crimp Fabrics (NCFs) are particularly difficult to characterize using this macro approach since important deformation mechanisms occur at the tow and stitch (meso) level. Consequently, a meso-scale modelling methodology for drape of NCF is presented that allows individual tow and stitch deformations and their interaction. The approach uses deliberately coarse modelling so that structural scale problems may be tackled. A further aim is subsequent coupling of results to a meso-scale resin infusion simulation of the draped fabric. Experimental testing at the tow and fabric levels provides necessary fabric deformation and permeability data to calibrate the models. One aim of the work is to develop a methodology for coupled drape and infusion simulation at the meso-scale. It is recognized some aspects still require improvement; never-the-less the studies presented and a final validation study for draping of a hemisphere and coupled infusion simulation have provided encouraging results compared to test measurements.