A simple model for characterizing non-uniform fibre-based composites and networks.

A mean-field model is presented that describes non-uniformities in the spatial distribution of fibres in networks and composites in terms of fluctuations in the local composition. The mean pore radius, specific surface area, lineal path function, and chord length probability density are expressed as functions of the fibre volume fraction within a heuristic formalism. The impact of statistical heterogeneities in the fibre distribution upon the elastic moduli is assessed within the semi-empirical Reuss-Voigt-Hill averaging scheme. Results from illustrative calculations suggest that such macroscopically averaged material properties are particularly sensitive to variations in the mean pore radius.