Quasi-static and dynamic response of open lattice structures for enhanced plateau stresses: Simulation and experiment validation

Lattice structures have gained significant attention due to their lightweight properties and exceptional capacity for specific energy absorption (SEA). This study focuses on designing a nature-inspired novel open flower lattice structure (NINOFL) to improve plateau stress and SEA under quasi-static and dynamic loading conditions . Multiple variations of NINOFL structures were designed and fabricated using the powder bed fusion (PBF) additive manufacturing (AM) process with SS316L material. The structures were developed in three-layered patterns within a 30 mm cubic framework, maintaining a consistent relative density of approximately 21 ± 1 %. To characterize the fabricated structures, Scanning Electron Microscopy (SEM) analyses were conducted to assess material distribution and identify potential defects arising from the AM process. Mechanical performance was evaluated through quasi-static compression tests using a universal testing machine (Instron 8801) and dynamic compression tests employing a Split Hopkinson Pressure Bar (SHPB) across varied high strain rates . Finite Element (FE) Analysis simulations performed with ANSYS software provided insights into the deformation mechanisms of the multi-layered structures under compression. The performance of the NINOFL structures was compared against standard Honeycomb (HC) and merged tessellated open-type lattice structures (MTLs) of similar relative density. Results demonstrated that the NINOFL structures outperformed their counterparts, exhibiting superior plateau stress distribution and significantly enhanced SEA. These findings establish the proposed NINOFL design as a promising solution for applications requiring optimized energy absorption and load-bearing capabilities.