Compressive strength and performance of horizontally and vertically oriented hybrid lattice structures manufactured by stereolithography

This study investigates the mechanical properties of hybrid lattice structures produced using stereolithography (SLA), a type of additive manufacturing (AM) technology. In the research, three different basic lattice geometries [Gyroid (A), Cross (B), and X-Cell (C)] were combined in both vertical and horizontal orientations to create hybrid structures. The specimens were produced using an acrylonitrile butadiene styrene (ABS)-like photopolymer resin and subjected to static compression tests. In the vertically oriented hybrid lattice structures, the homogeneous Gyroid (AAA) specimen exhibited the highest compressive strength (4.20 MPa), energy absorption capacity (2.53 MJ/m³), energy absorption efficiency (62.43%), and specific strength (8.17 N·m/kg). In the hybrid structures, it was observed that the top layer played a critical role in the overall strength of the structure, with ABC and ACB specimens containing Gyroid showing high initial stiffness and strength. In the horizontally oriented hybrid lattice structures, the homogeneous Gyroid (AAA) structure also demonstrated the highest energy absorption (approximately 3.65 MJ/m³) and specific strength (6.29 N·m/kg) performance. Among the hybrid configurations, BAC (Cross-Gyroid-X-Cell) and CAB (X-Cell-Gyroid-Cross) structures, where the Gyroid unit is positioned in the middle, stood out with energy absorption capacities of 3.09 and 3.02 MJ/m³, respectively. These arrangements exhibited more controlled and gradual collapse behavior, ensuring a more stable and higher energy absorption performance. This study contributes to the literature on the mechanical behaviors of hybrid lattice structures produced using the SLA method. The findings show that the type and arrangement of lattice cells have a significant impact on the mechanical properties of the structures.