COVERAGE AND MECHANICAL PROPERTIES OF SPRAY-PROCESSED RANDOM CARBON FIBRE COMPOSITES

摘要

The F3P process has been developed to produce affordable, lightweight body structures using carbon fibre roving. Processing larger tows is attractive from a cost perspective but attaining a homogeneous fibre distribution is increasingly difficult. Large variations in local volume fraction are translated into mechanical property variations, particularly for thin components; therefore this paper investigates methods for achieving uniform fibre coverage. A process simulation has been developed to enable material and process related parameters to be studied. A method for filamentising large tows has been developed to split the roving down into smaller clusters of filaments. The effects of inducing filamentisation are discussed, supported by in-plane tensile experimental data. Methods for quantifying the level of filamentisation, in terms of the bundle size distribution, have been assessed and analytical models for stiffness prediction of random composites have been reviewed.