Enhancing the mechanical performance of additively manufactured auxetic structures through design modifications: experimental and numerical analysis

Abstract Auxetic structures are highly attractive because of their unique characteristics. They offer manipulable mechanical properties, negative Poisson’s ratio, lightweight construction, and exceptional energy absorption capabilities, making them suitable for a wide range of engineering applications. In this study, we present three novel in-plane auxetic structures based on the modifications of the re-entrant unit cell. These designs focus on enhancing the energy absorption capacity while maintaining the specific properties, such as a negative Poisson’s ratio and lightweight construction. The structures are additively manufactured using thermoplastic polyurethane and subjected to compression tests. Numerical analysis is also performed to verify the experimental results. While the experimental and numerical results are in good agreement, two of the proposed designs demonstrate significant improvements in energy absorption. The maximum enhancement is 1250% in the energy absorption capacity and 860% in the ratio of energy absorption to weight compared to the base re-entrant structure, with improved negative Poisson’s ratio values. The results of the study indicate that our innovative structures are promising as a new generation of auxetic structures with enhanced energy absorption capacity and significant negative Poisson’s ratio values.