In-Plane Crushing Response of a Novel Arc-Curved Hybrid Honeycomb with Negative Poisson's Ratio

Incorporating arc-curved configuration into auxetic honeycomb can evenly distribute pressure, reduce stress concentration, and avoid fracture. In this work, a novel arc-curved chiral star-shaped honeycomb (ACSH) has been proposed by combining the chiral honeycomb (CH), the star-shaped honeycomb (SSH), and arc-curved configurations. The crushing response of the ACSH is studied experimentally and numerically. In order to verify the accuracy of simulation, quasi-static compression experiment is carried out on the ACSH sample fabricated by 3D printing. Subsequently, the crashworthiness of the ACSH is compared with other honeycombs. Particularly, under the crushing velocity of 2 m s(-1), the ACSH exhibits exceptional specific energy absorption, which is 179% higher than that of the conventional SSH. Additionally, it is also found that introducing arc-curved configuration can effectively reduce initial peak stress. Moreover, the effect of functionally graded design on crashworthiness is systematically analyzed. The findings indicate that the initial peak stress decreases with the decrease of gradient rate. When crushing velocity increases to 80 m s(-1), the SEA of the ACSH increases with the increase of gradient rate. This work investigates the crushing response of a novel honeycomb, which can provide a reference for designing and optimizing novel lightweight honeycombs with better crashworthiness.