In-Plane Quasi-Static Crushing Behaviors of a Novel Reentrant Combined-Wall Honeycomb

The innovative design of microstructure topology is of great significance to improve the energy absorption performance of honeycombs. In this paper, by embedding a hexagonal substructure in each inclined wall of the traditional reentrant (RE) honeycomb, a novel auxetic honeycomb, called reentrant combined-wall (RCW) honeycomb, is developed for improving energy absorption. Combining the experimental methods, numerical simulations, and analytical analyses, we systematically studied the in-plane quasi-static behaviors of the proposed honeycomb structure. It can be found that the deformation of the RCW honeycomb has a transitional stage, which makes a significant stress enhancement. During the crushing process, the Poisson’s ratio of the RCW honeycomb keeps negative and is lower than that of the RE honeycomb. Besides, numerical and analytical analyses show that the stress-strain response of the RCW honeycomb has a good designability. Further, the analysis of specific energy absorption (SEA) is also performed, in which the RCW honeycomb shows a significant superiority over the RE honeycomb, with the SEA value almost twice that of the latter. Therefore, it can be concluded that the proposed novel structure has tangible improvements in the crushing strength, auxetic performance, and energy absorption, which deserves more attention in future work.