Evaluation of the mechanical properties and energy absorption in a novel hybrid cellular structure

The present study proposes a novel hybrid cellular structure consisting of unit cells with different geometrical designs to tailor Young's modulus and improve the energy absorption capability. An analytical model was developed to predict the mechanical properties of the baseline cellular structure. Using the particle swarm optimization (PSO) algorithm, the geometry of two unit cells is designed with the maximum (Type-2) and minimum (Type-1) stiffnesses compared to the baseline structure. These two unit cells were utilized to design the properties of the novel hybrid cellular structure for an optimized energy absorption capability. For evaluating Specific Energy Absorption (SEA) in the hybrid structure, the samples were 3D printed and subjected to compression testing. Finite Element Modeling (FEM) was also conducted for further study by assuming the elasto-plasto-damage properties. The results indicate that the novel hybrid structure shows a 90% improvement in SEA by reducing the weight by 70% compared to the Type-1 cellular structure. The EA of various polymers, including PLA, PA12, PP, PETG, ABS, TPU, and FLEX, were examined by utilizing the FEM as a virtual test method. Based on the results, SEA capacity in cellular structures can be increased by optimizing the topology and selecting the appropriate material containing high elastic modulus and failure strain.