Statistical modeling of in-plane permeability of non-woven random fibrous reinforcement

A methodology has been proposed for statistical characterization of transport behavior of a typical random fibrous medium, i.e. the Chopped Strand Mat (CSM). For any given digital images of fabric sample, statistical description of the random microstructure is employed to evaluate the permeability field, in the framework of the statistical continuum approach. By choosing suitable sampling strategy, the evaluated permeability field can be used to predict the realistic fluctuation in the flow pattern in the RTM mold-filling process with a high accuracy, as validated by the radial injection experiments. The method can be generalized to other random fibrous media. Using a database of CSM samples, statistical characterization of fiber volume fraction and permeability fields is performed respectively. Important statistical properties, e.g. the RVE size, marginal PDF and correlation length have been provided for the transport properties of the CSM, as the basis for the input data for stochastic simulation of composite processing.