ANALYSIS OF THREE-DIMENSIONAL MICROSCOPIC STRESS DISTRIBUTIONS AT A FREE EDGE OF A UNIDIRECTIONAL CFRP LAMINATE

In this study, the distributions of microscopic stresses at a free edge of a unidirectional carbon fibre-reinforced plastic laminate (CFRP laminate) are analysed three-dimensionally, based on a homogenisation theory. For this, the mathematical homogenisation theory for elastic materials is reconstructed for unidirectional CFRP laminates with free edges using a traction-free boundary condition. The present theory is then applied to the analysis of microscopic stress distributions at a free edge of a unidirectional carbon fibre/epoxy laminate subjected to in-plane uniaxial tension. It is shown that microscopic shear stress noticeably occurs at the free edge, especially at the interface region between a carbon fibre and its surrounding epoxy matrix.