بررسی هندسه و ظرفیت جذب انرژی در ساختارهای درون سو و ستاره ای

Auxetic structures, due to their negative Poisson’s ratio, exhibit distinctive mechanical properties such as high energy absorption capacity, favorable stress distribution, and enhanced resistance to dynamic loading. These characteristics have made them attractive as advanced energy absorbers in industries such as aerospace and automotive engineering. In this study, the mechanical behavior and energy absorption performance of three families of auxetic structures, including re-entrant, star-shaped, and hybrid configurations, were numerically and comparatively investigated. First, the mechanical properties of the base material were determined through tensile testing in accordance with ASTM D638 using specimens fabricated by the FDM method with PLA+ filament. Then, the geometries of the structures were modeled in ABAQUS, and their behavior under quasi-static in-plane compressive loading was simulated. To evaluate performance, indices including Specific Energy Absorption (SEA), Mean Crushing Force (MCF), Initial Peak Crushing Force (PCF), and Crushing Efficiency Factor (CEF) were extracted and analyzed.The results showed that in the re-entrant family, the second-order structure, with an SEA of 4.8 kJ/g, performed better than the base specimen. In the star-shaped family, the second-order model achieved the best result, with an SEA of 6.9 kJ/g. Among the hybrid structures, the concentrated design exhibited the highest energy absorption capacity, with an SEA of 12.3 kJ/g, while the corner design showed a safer response in terms of initial peak crushing force. These findings confirm the significant role of geometric complexity in improving energy absorption and crushing stability.