Comparative Investigation of Compression and Energy Absorption Performance of Modified Re-Entrant Auxetic Structures

In this study, the collision behaviors of three different auxetic unit cell designs (diagonal re-entrant, split re-entrant, and arrowhead re-entrant) with negative Poisson's ratios used in energy absorption and available in the literature were investigated. A new model was designed inspired by the re-entrant model and the rib model. The models were subjected to quasi-static compression tests using computer-aided engineering simulations, and ABS and PETG materials, commonly used in additive manufacturing, were used in these tests. Each model was modeled as a 100x100x20 mm lattice structure consisting of 4x4 unit cells. In the analyses, the element size was set to 1 mm using mesh convergence. According to the results obtained in the study, the split re-entrant model achieved the highest maximum force value among all materials, while the arrowhead re-entrant model exhibited the lowest maximum force value. The new design re-entrant rib model exhibited a more balanced performance compared to other models. When evaluated on a material basis, ABS exhibited more stability, while PETG stood out in terms of impact resistance and displacement capacity. In this context, the superior performance of the new model in comparison with other models in analyses conducted with different materials demonstrated the advantages of the new designs over standard models.