Influence of stochastic fibre angle variations on the permeability of bi-directional textile fabrics

To predict the range of probable outcomes of resin injections in Liquid Composites Moulding (LCM) processes for non-uniform textiles, a stochastic injection simulation procedure has been implemented. The local variations in textile properties are deduced from the normally distributed fibre angles. The global permeability and its variance are determined from the global flow front propagation. The simulation results suggest that the global permeability is mainly determined by fabric shear behaviour, while the dimensions of the unit cell locally affect the flow front shape. For the example of an actual composite component, stochastic simulation shows its potential for predicting the range of probable mould filling times and filling patterns. While the global permeability value can be determined from the simulations with good accuracy, quantitative comparison with experimental values suggests that the actual permeability variation is underestimated due to limitations of the stochastic model.