Compressive and energy absorption behavior of origami-inspired CF-PLA infill structures fabricated by material extrusion

This study aims to investigate the compressive behavior and energy absorption performance of origami-inspired infill geometries fabricated using material extrusion additive manufacturing with short carbon fiber reinforced PLA (CF-PLA). The novelty of this work lies in combining art of folding paper based origami geometries (Hexagonal Kresling and Zig-Zag Origam) with CF-PLA material to achieve enhanced stiffness and specific energy absorption (SEA) compared to conventional infill patterns (line, octet, cross, and triangle). The origami and convention geimentries samples 3D printed and tested under compressive loading conditions. The Hexagonal Kresling pattern had the highest compressive strength (11.63 MPa), while the Zig-Zag Origami pattern had the best stiffness (3.48 kN/mm) and specific energy absorption (2.976 J/g). The experimental testing, a theoretical evaluation was performed using the Gibson–Ashby cellular solid model, Kelly–Tyson shear-lag theory and buckling mechanics to explain the observed stiffness enhancement and SEA behavior. Also, microstructural analysis confirmed that stress distributed evenly and that there was little layer delamination in origami-based (Zig-Zag) sample. The combination of origami-inspired design and CF-PLA enables lightweight, high-strength components with improved energy absorption and structural integrity for automotive and aerospace applications. This study provides a foundation for further geometrical optimization in additive manufacturing using origami-inspired reinforcement.