Flexural Behavior and Fracture Analysis of Additively Manufactured Short Carbon Fiber‐Filled Acrylonitrile Butadiene Styrene L‐Brackets Architected With Triply Periodic Minimal Surfaces Lattices

ABSTRACT

Balancing lightweight design with load‐bearing capability remains a central challenge in intelligent unmanned systems, where L‐shaped brackets frequently operate under complex loading. In this study, five triply periodic minimal surface (TPMS) lattice topologies were integrated into carbon fiber‐reinforced acrylonitrile butadiene styrene (CF/ABS) structures and fabricated via fused deposition modeling (FDM). Mechanical behavior was evaluated through four‐point bending tests, complemented by finite element analysis (FEA) to examine internal stress transfer. The results reveal that performance differences arise from how each topology organizes force transmission rather than from geometry alone. Among the structures, the Diamond configuration shows the most efficient response, achieving a mass‐normalized flexural strength of 13.54 MPa·g ⁻¹ , approximately 70% higher than that of Split‐P. Its interlaminar tensile strength (ILTS) reaches 7.28 MPa, surpassing the Gyroid structure by 90%. FEA results indicate that the Diamond topology forms directional, truss‐like load paths, whereas the Gyroid distributes stress more diffusely. This contrast in force flow behavior accounts for an observed strength difference of approximately 50%. These findings establish a direct link between topology, force transmission, and macroscopic performance, offering guidance for the design of lightweight, additively manufactured load‐bearing structures.