Mechanical Characterization and Comparative Analysis of Energy Absorption Capacities of Carbon Fiber Reinforced PLA + Vintiles and Tesseract Lattice Structures

This study experimentally investigates the mechanical behavior and performance of Vintiles and Tesseract lattice structures, produced from PLA+ (polylactic acid) filament using additive manufacturing methods and enhanced with carbon fiber reinforcement, under various tests. In this context, the biomimetic Vintiles structure, exhibiting bending‐dominant deformation characteristics, and the high‐node‐number Tesseract structure, exhibiting stretch‐dominant behavior, were evaluated comparatively. Mechanical behavior was investigated in terms of structural stiffness and energy absorption through quasi‐static compression tests, bending strength through three‐point bending tests, and responses to different loading conditions through dynamic impact tests. Experimental results showed that the Tesseract structure exhibited high initial stiffness and superior specific energy absorption. On the other hand, the Vintiles structure was found to exhibit more stable deformation and damping behavior. Carbon fiber reinforcement significantly increased bending strength and specific energy absorption, especially in the Vintiles structure, while providing a more limited improvement in the Tesseract structure. Macro‐damage analyses revealed that impact velocity and fiber reinforcement were decisive in the damage mechanisms. Furthermore, although the Tesseract structure is typically classified as bending‐dominated according to Maxwell's stability criteria, it exceptionally exhibited a response governed by stretch‐dominated effects.