محمدامين ادريسي

This research presents the experimental analysis an‎d statistical modeling of the mechanical behavior of auxetic lattice structures with elliptical cell geometry, fabricated from PLA using 3D printing technology. The primary objective is to quantitatively determine the influence of key geometric variables—including the elliptical aspect ratio (A) in the range of 1 to 3 an‎d the thickness-to-minor-diameter ratio (B) in the range of 0.06 to 0.12 - on the output properties: effective Poissonʹs ratio, elastic modulus, compressive strength, an‎d toughness. A Central Composite Design experiment was employed in the Design-Expert software for designing the tests an‎d extracting regression models, which confirmed a high fit accuracy (with R2 ranging from 0.83 to 0.99). Analysis of Variance results indicated that all mechanical properties are significantly influenced by the interactive an‎d nonlinear effects of parameters A an‎d B. The most significant finding regarding auxetic performance was the strong significance of the A2B nonlinear interaction effect. The strongest auxetic behavior (lowest effective Poissonʹs ratio) is achieved in the region of the lowest wall thickness (low B) an‎d intermediate aspect ratios (intermediate A). Conversely, compressive strength an‎d elastic modulus are primarily enhanced by increasing the thickness (high B). A simultaneous optimization analysis was performed to achieve the best compromise between the conflicting objectives (maximum strength an‎d minimum Poissonʹs ratio), which resulted in a final compressive strength of 317.7 MPa an‎d an effective Poissonʹs ratio of – 0.135 at the optimum point of A = 1 an‎d B = 0.12. These results provide a comprehensive understan‎ding of the structural mechanisms an‎d quantitative design strategies for producing high-performance auxetic structures for engineering applications.

سازه هاي آگزتيك , نسبت پواسون , سلول هاي بيضوي , مدلسازي سطح پاسخ , مقاومت فشاري

Auxetic Structures , Poissonʹs Ratio , Elliptical Cells , Response Surface Methodology , Compressive Strength

Mohammad Amin Edrisi

Dr. Habibollah Akbari