In-plane dynamic impact behaviors of a self-similar concentric star honeycomb with negative Poisson’s ratio

Abstract

Star-shaped honeycomb with negative Poisson's ratio has the advantages of low weight, high specific strength and high energy absorption, thus having a wide range of applications in improving the crashworthiness of cars. To improve the crashworthiness of the SSH, a self-similar concentric star honeycomb (SCSH) is proposed. The finite element model of the SSH is established to compare with the existing reference results. The dynamic impact behavior of the SCSH at three different impact velocities is studied. The results show that the SCSH has higher plateau stress and energy absorption than the SSH at different velocities, especially at low-velocity and medium-velocity. In addition, the effects of wall thickness, cell wall angle, and the number of concentric walls on energy absorption are studied. It can be seen from the parameter analysis that wall thickness and the number of concentric walls have a greater influence on crashworthiness. To better simulate the actual collision scene, the crashworthiness of the SCSH under oblique loading is studied, and it is found that the SCSH still had better energy absorption than the SSH. Therefore, the design of new cellular metamaterials allows obtaining structures with better energy absorption ability.