Multi-material 3D printing of continuous carbon fibre reinforced thermoset composites with tailored fibre paths and bespoke conforming thermoplastic moulds
Haoqi Zhang, Aonan Li, Jiang Wu, Dongmin Yang
Abstract
This paper proposes a novel additive manufacturing approach for rapid, integrated fabrication of complex structures made from 3D-printed composites with low porosity and a high continuous fibre content. Continuous carbon fibre reinforced epoxy composites with >50% fibre volume fraction were printed in parallel with short carbon fibre reinforced polyamide-6 (PA6) conforming moulds which have a melt temperature higher than the curing temperature of epoxy. The research further optimised the continuous fibre paths through experiments and as-manufactured finite element simulations, using 3D-printed truss structures under three-points bending as a case study. Additionally, the incorporation of polylactic acid (PLA) with a lower melting temperature, enhanced compatibility and bonding between the epoxy and PA6. The approach was applied and demonstrated for a lightweight composite wing box using tailored material interface and customised reinforcement alongside varying infill densities. This approach also opens up possibilities for assembling lightweight, large-scale composite structures using 3D-printed high-performance continuous carbon fibre units. • Novel AM method achieves >50% fibre volume fraction in 3D-printed composites. • Multi-material printing integrates thermoset composites and thermoplastic moulds. • PLA enhances interfacial bonding with epoxy through co-melting and curing. • Optimised fibre paths and infill densities enable lightweight, high-strength structures. • Demonstrated scalable fabrication of composite aerofoil with tailored reinforcements.