Analysis and Optimization of Energy‐Absorbing Characteristics of Additively Manufactured Carbon Fiber Reinforced Nylon Composite Biomimetic Tubes

ABSTRACT This study proposed a 3D‐printed horsetail biomimetic multi‐cell bi‐tube (HBMB) structure fabricated from carbon fiber‐reinforced polyamide 6 (PA6‐CF), whose design was inspired by the tree‐like branching cross‐sectional mode of horsetail stems, and further introduced closed units at the rib plate branches to enhance impact resistance. We developed a finite element model of the 3D‐printed HBMB structure, and further used this model to systematically analyze the effects of the number of rib plates and closed cell shape on the structural compressive performance. Based on the technique for order preference by similarity to ideal solution, we identified the HBMB‐A4 structure configured with six ribs and square closed units as the optimal solution in terms of comprehensive performance. Subsequently, we adopted the improved multi‐objective snake optimization algorithm to perform multi‐objective optimization of the inner diameter, closed cell size, and wall thickness of this structure, and then verified the prediction accuracy of the optimized model. The validation results indicated that the prediction errors for peak crushing force and specific energy absorption were as low as 1.44% and 4.63%, respectively, thus verifying high accuracy in forecasting the axial compressive mechanical response of 3D‐printed PA6‐CF HBMB structures. This study clarifies the structure‐performance coupling relationship of 3D‐printed fiber‐reinforced composites, thereby laying a theoretical foundation for the future application of 3D‐printed carbon fiber‐reinforced composites in energy‐absorbing protection systems for transportation equipment.