In-plane crushing response and energy absorption of two different arranged circular honeycombs

Circular honeycombs have been widely used in many fields due to their excellent mechanical properties recently, however, circular honeycombs with different arrangements have been rarely studied. In this paper, two circular honeycombs with different arrangements were designed and fabricated using a 3D printer. Both honeycombs were investigated by experiment and finite element (FE) analysis to compare their performance. It is worth noting that both honeycombs possess the same relative density. The accuracy of the FE models was validated by comparing them with experimental results and relevant reports. Subsequently, a series of numerical studies were conducted to analyse the in-plane dynamic crushing behaviour and energy absorption characteristics at different impact velocities. Based on different experiment deformation modes were identified from the observation of results respectively. Additionally, continuous circle honeycomb (CCH) exhibits a higher reaction force but is prone to fracture. On the other hand, spacing circle honeycomb (SCH) possesses a lower reaction force but offers greater stability due to its ability to flex and release force. As a result, SCH can effectively absorb energy and demonstrates superior crushing capacity compared to CCH. To investigate and compare the plateau stress and energy absorption of these honeycombs, the FE method was used, which also involved a detailed analysis of the impact velocity and relative density of the honeycomb. It was observed that the crushing stress and energy absorption of SCH were higher than those of CCH with the same impact velocity and relative density. According to the one dimensional shock wave theory, empirical formulas for two circular honeycombs to predict the plateau stress are given respectively with the maximum error lower than 12%. This paper aims to offer valuable insights for the design of different configurations, with the goal of improving the crashworthiness and energy absorption capacity of a specific honeycomb structure