Stress-driven infill mapping for 3D-printed continuous fiber composite with tunable infill density and morphology

Continuous fiber composite via additive manufacturing is an emerging field that extends the design freedom of composite structure as well as integrates with the digital fabrication approach. The path planning for continuous fiber is highly freedom to achieve tunable and desirable lightweight performance. Herein, a wave projection function is proposed to design the infill morphology and control the infill ratio corresponding to a specific vector field. The infill ratio and path orientation are simultaneously mapped with mechanical stress field distribution. The path planning algorithm via solving the traveling salesman problem (TSP) is employed to generate continuous fiber trajectories with minimized cutting points. As fabricated composite structure shows outstanding performance over these with conventional Zig-Zag infill pattern, which possesses identical infill ratio. The proposed infill approach can integrate with the topology optimized structure to concurrently optimize the infill fiber path and structural configuration. This generative design for composite structure is a typical AM-driven approach, which exhibits strong advantages to create adaptive infill patterns with complex geometry.