Multi-strategy integrated general toolpath planning framework for continuous fiber-reinforced polymer additive manufacturing

This study presents a general toolpath planning framework integrated with multiple path generation strategies for continuous fiber-reinforced polymer additive manufacturing (CFRP-AM). Built upon the concept of offset weighting, the proposed method achieves strong adaptability to complex geometries and enables flexible fiber placement while providing tunable mechanical performance with excellent properties. To further enhance manufacturability and quality, a path filtering process and a novel optimization approach are introduced to mitigate potential fiber damage during deposition. Finite element analysis and mechanical testing of specimens fabricated with different strategies reveal that structural stiffness increases with the offset weight of the shape contour, while a balanced distribution of offset weights between shape and hole contours yields a higher load-bearing capacity. Moreover, varying offset weighting strategies cause migration of resin-rich regions, influencing local stress distributions and failure modes. A hybridization of different offset weighting strategies can further improve mechanical strength. Specifically, the hybrid-strategy specimen demonstrates a 22.26% increase compared with the strongest single-strategy specimen. This work establishes a novel toolpath planning framework for CFRP-AM, providing a solid foundation for future hybrid strategies while enabling enhanced control over fiber layout and improved structural performance in complex composite parts.