Tensile behaviour of hybrid fibre architectures of randomly oriented strands combined with laminate groups

In this work, the tensile behaviour of co-moulded hybrid fibre architectures of randomly oriented strands (carbon/PEEK) combined with laminate groups (cross-ply, angle-ply and quasi-isotropic) is studied. The effects of varying the thickness of the laminate group relative to that of randomly oriented strands, stacking sequence of the architectures within a hybrid specimen, and the ply stacking sequences within the laminate group are quantified. Processing benefits of hybridization such as reduction in warpage and strand waviness are discussed. The tensile behaviour of hybrid fibre architectures is quantified and compared with that of randomly oriented strand specimens, base laminate groups and aluminum 7075. In addition, tensile failure modes have been investigated. Significant improvements in the mechanical properties of randomly oriented strands are observed with small proportions of laminate groups in the specimen. In addition, hybrid fibre architectures exhibit a positive synergy or a positive deviation from the rule-of-mixtures in the overall stiffness and strength behaviour when stacked in specific configurations, despite the same fundamental fibre type and matrix system.