The internal architecture of fused filament fabrication (FFF) components plays a critical role in determining their mechanical and energy-absorption behavior. Despite the increasing application of sustainable wood-PLA biocomposites in additive manufacturing, a comprehensive understanding of how different commercially available infill architectures influence their crashworthiness performance remains limited. In this study, wood-PLA biocomposite tubes were fabricated using eight widely employed infill patterns, namely Grid, Lines, Triangles, Cubic, Octet, Concentric, Zig-zag, and Gyroid. The crashworthiness performance of the specimens was evaluated through quasi-static axial compression tests by analyzing energy absorption (EA), specific energy absorption (SEA), initial peak force (IPF), mean crushing force (MCF), and crushing force efficiency (CFE). The results demonstrated that infill architecture significantly affected the crushing response and energy dissipation capability of the printed structures. The Zig-zag pattern exhibited the highest EA (140.9 J), MCF (7.05 kN), and CFE (95.2%), indicating superior progressive crushing behavior and energy absorption capability. The Grid architecture achieved the highest SEA (16.3 J/g), highlighting its excellent material utilization efficiency. In contrast, the Concentric pattern exhibited the lowest IPF (4.23 kN), but also showed the poorest overall crashworthiness performance. The findings demonstrate that infill architecture is a dominant design parameter governing the crashworthiness performance of FFF-printed wood-PLA biocomposites and provide practical guidelines for the design of lightweight and energy-absorbing sustainable structures.
