  This paper presents a new concept to place continuous curved fibres for CFRP
composites, which can be fulfilled by potential additive or hybrid
manufacturing technology. Based on the loading condition, principal stress
trajectories are generated through finite element analysis (FEA) and used as
the guidance of the placement paths for carbon fibres. Three numerical cases,
an open-hole single ply lamina under uniaxial tension and an open-hole
cross-ply laminate under biaxial tension and normal pressure, are studied and
compared with traditional reinforced composites with unidirectional fibres. The
modelling results show that the stress concentration in both fibre and matrix
are reduced significantly by the curved fibre placement and the stiffness of
CFRP composites have been improved. This concept of performance-driven
optimization method could lead to a useful tool for the design of future 3D
printing process for fibre reinforced composites.
