Quasi-Static and Dynamic In-Plane Mechanical Properties of Multi-Deformation Mode Honeycombs

To address the issue that the engineering application of conventional auxetic honeycomb metamaterials (AHMs) is limited by poor support performance, a novel multi-deformation mode honeycomb (MDMH) is proposed through the design of the internal contact behavior and deformation compatibility. A finite element (FE) numerical model is established to investigate the in-plane mechanical properties of the MDMH under quasi-static and dynamic compression. The static contact deformation modes in different compression phases are compared to reveal the stress transformation mechanism, and the stress fluctuations under dynamic impact are explained from the perspective of the stepwise contact and inertial effect. Based on the local instability analysis, three improved MDMHs with different reinforced ribs are developed to enhance the configuration stability. The in-plane mechanical properties of improved MDMHs are explored to verify the effectiveness of the design for stability enhancement. Moreover, the effects of wall thickness and configuration angle on the stress-strain characteristics are systematically discussed. The results indicate that the static stiffness of the MDMH is significantly enhanced when the deformation mode transformation triggered by the designed internal contact is produced. The stress characteristics of the MDMH are sensitive to the impact velocity due to the inertia effect. The configuration stability enhancement design with attached reinforced ribs effectively improves the ultimate support performance and energy absorption capacity. Therefore, this work provides an innovative strategy for enhancing the mechanical properties of AHMs by improving the contact behavior and configurational stability under compression deformation.