Theoretical Modeling of the Plateau Stress of a Modular Discrete Auxetic Honeycomb Based on Mortise and Tenon Principle

Auxetic metamaterials process unconventional negative Poisson’s ratio (NPR) and superior mechanical properties, but their complex monolithic designs often rely on costly additive manufacturing (AM), limiting practical applications. To address these challenges, we develop a mortise-and-tenon modular discrete auxetic honeycomb (MDAH-MT) which enables scalable fabrication and structural reconfigurability. In this work, we investigate the plateau stress — a key indicator of crashworthiness — of the MDAH-MT through theoretical analysis and numerical simulations. Based on the underlying deformation mechanisms and the energy method, theoretical models of the plateau stresses under quasi-static compression, low- and high-velocity impacts are established. Finite element (FE) simulations validate these models, showing good agreement with the theoretical predictions. The crashworthiness and structural stability of the MDAH-MT are further evaluated, revealing that it not only provides effective energy absorption but also exhibits superior self-locking stability and transmits lower forces to the protected object compared with other modular discrete energy-absorbing structures. This study provides theoretical foundations for the applications of the MDAH-MT in engineering fields related to crash protection and safety.