High-performance reusable honeycomb metamaterials designed via twin-induced topology

The honeycomb structure, as one of the earliest two-dimensional metamaterials recognized and utilized by humans, has been extensively employed in various applications due to its ease of production, lightweight and high strength. However, with the ever-increasing demands for structural performance and environmental sustainability in modern engineering applications, the specific strength and specific stiffness of traditional hexagonal honeycombs can no longer meet the requirements. Inspired by the concept of twin-induced strengthening in metals, this work designed two types of modified honeycombs with exceptional mechanical properties. Experimental results demonstrated that our metamaterials exhibited outstanding relative stiffness and relative strength, even surpassing those of most three-dimensional metamaterials. Furthermore, one of the structures demonstrated a remarkable reusable capability of up to seven cycles before localized failure occurred. Additionally, by analyzing the anomalous phenomena observed during repeated quasi-static compression tests, this study revealed the critical role of self-contact effects in enabling reusability and enhancing mechanical performance. In summary, this research represents the first exploration of high-performance reusable metamaterials and suggests a promising direction for further studies in this field.