Design of high-stiffness continuous fiber additive manufacturing stiffened structures via width-constrained topology optimization and continuous-load-transfer path planning

Additive manufacturing (AM) offers enhanced design freedom and flexibility for continuous fiber composite structures. This work introduces width constraints into a framework for concurrent topology and fiber orientation optimization for continuous fiber-reinforced stiffened structures. Maximum stiffener width is controlled by incorporating porosity within fiber-aligned rectangular search regions, while minimum width is enforced via auxiliary real design variables. Crucially, the fiber-aligned search regions inherently align the optimized fiber orientations with the stiffener’s principal direction, ensuring efficient axial load transfer. This approach effectively mitigates path planning difficulties and load-bearing failures associated with excessively large or small stiffener widths. Finally, after topology optimization and model reconstruction, a path planning strategy is proposed that ensures both global fiber path continuity and, more importantly, the continuous load transfer along the fibers, followed by fabrication and experimental validation of the optimized structures. Experimental results demonstrate that introducing through-fiber reinforcement with continuous-load-transfer paths along the fibers in stiffener intersection zones can significantly enhance the stiffness of continuous fiber composite structures, highlighting its substantial potential for high-load-bearing stiffened structures applications.