High-performance curved sections in 3D printed continuous carbon fibre reinforced thermoplastic composites using aligned fibre deposition

This paper presents high-performance curved sections in 3D printed continuous carbon fibre reinforced thermoplastic composites using an aligned fibre deposition (AFD) method on a 6-axis robotic arm. 3D printed curved composite beams using both AFD and conventional methods are mechanically tested under four-point bending and scanned by X-ray computed microtomography (μCT) to characterise the fibre distribution and develop image-based finite element models. Compared to conventional printing method using a commercial nozzle, the proposed AFD method significantly improves the fibre alignment and reduces void content in the printed composites, and the curved beam strength is calculated as 204.2 N and 224.5 N for the cases of 7 mm and 15 mm radius of curvature, achieving an improvement of 34.0% and 45.3%, respectively. The modelling produces excellently matched stiffness with the experimental measurement, providing useful insights into the stress and strain distributions. The combination of experimental data and modelling results shows that the alignment of fibres in the curved composite beams plays a key role in improving mechanical performance and determining the final failure mode.