Effects of fibre–fibre interaction on stress uptake in discontinuous fibre reinforced composites

The response of discontinuous fibre composites to mechanical loading is regulated to a large extent by the cooperative action of the fibres but the underlying effects of fibre–fibre interaction remain unclear. Here, finite element analysis of a simple 3D representative volume element of an aligned discontinuous fibre composite reveals that the interaction of fibres—described by the fibre–fibre lateral separation distance and axial overlap length—influences the fibre stress uptake during elastic stress transfer. In particular, fibre–fibre lateral separation influences the magnitude of the stress; interestingly axial overlap produces a stepwise stress discontinuity in the fibre.