تحليل و بررسي عددي و تجربي ميزان جذب انرژي يك ساختار آگزتيك اصلاح شده

The design an‎d development of lightweight structures with high energy absorption capacity have become important research topics in mechanical engineering an‎d materials science. In this study, three modified re-entrant auxetic structures with circular, elliptical, an‎d ellipse–rhombus hybrid geometries were designed, fabricated using three-dimensional (3D) printing technology, an‎d investigated through both experimental an‎d numerical analyses to improve the energy absorption performance. In addition, the effect of filling the cellular structures with expan‎dable polyurethane foam was eva‎luated to further enhance their energy absorption capability. The results showed that the modified circular model exhibited 7% an‎d 45% higher specific energy absorption than the elliptical an‎d ellipse–rhombus hybrid models, respectively. Although the mass of the circular model was 3% higher than that of the ellipse–rhombus hybrid model, it was 3% lower than that of the elliptical model. Furthermore, filling the circular structure with polyurethane foam increased its specific energy absorption by approximately 29% compared with the hollow configuration. A comparison between the experimental an‎d numerical results revealed that the discrepancy between the two approaches remained below 15% for all specimens, indicating the satisfactory accuracy an‎d reliability of the numerical model in predicting the structural response. Overall, the findings demonstrate that combining a modified re-entrant geometry with a circular configuration an‎d polyurethane foam filling is an effective approach for improving the energy absorption performance of auxetic structures. These results provide useful insights for the design an‎d development of protective structures, impact absorbers, an‎d lightweight energy-absorbing systems for engineering an‎d industrial applications.

حامد رضوي بني

بهمن اسدي , ابوالحسن عسگر شمسي