Development of novel auxetic-nonauxetic hybrid metamaterial

Cellular metamaterials with positive PR (non-auxetic) and negative PR (auxetic) have been well covered in literature. However, to author’s knowledge, topologies with zero PR is limited to few studies, although they have higher impact energy absorption potential compared to conventional auxetic and nonauxetic topologies. Hence, the aim of this paper is to propose a new hybrid topology that combines auxetic and non-auxetic nature, achieving near zero PR. An analytical approach was employed to analyze considered geometries. A non-linear computational model was then developed using Abaqus software to investigate their behavior under dynamic impact. The hybrid topologies showed a mix between the X-shaped progressive collapse of the uniform non-auxetic honeycomb and the lateral shrinkage of the uniform auxetic re-entrant. The hybrid topologies outperformed conventional auxetic and nonauxetic topologies with higher Specific Energy Absorption (SEA), showing superior performance when subjected to dynamic impact. The proposed sacrificial hybrid cellular metamaterial can be used in different scales to protect civil and defense vulnerable structures.