Experimental and numerical investigation on 2.5-dimensional nature-inspired infill structures under out-plane quasi-static loading

The 2.5-dimensional (2.5D) infill structures are gaining more attention due to their better energy absorption capabilities and lightweight. The additive manufacturing eases the fabrication of these structures and made them accessible for industrial and transport applications. The present work is focused on enhancing energy absorption capability, and mean crush force (MCF) for a novel nature-inspired 2.5D infilled structure through nature-inspired 2.5D geometries. Six nature-inspired geometries are considered for a comparative analysis with the proposed novel snowflake-inspired 2.5D infilled structure to sustain under quasi-static out-plane loading. These structures are cylindrical shells filled with different infill configurations and maintained at constant volume. The structures are fabricated using three-dimensional printing through the digital light processing technique with photopolymer resin and tested under compressive out-plane quasi-static loading conditions. Numerical simulations were performed by ANSYS and compared with experimental results to corroborate the reliability. The effect of infill configurations and supported ribs on the crushing behaviour is discussed in detail. The results reveal a significant improvement in MCF, specific energy absorption, and confined crushing deformation for the proposed lightweight 2.5D infill structures.