Advantage and drawbacks of auxetic structures obtained by laser cutting
摘要
The industrial deployment of metallic auxetic structures requires a clear understanding of how fabrication technologies and structural parameters influence their mechanical behavior. However, existing studies mainly emphasize geometric design, while the influence of manufacturing-induced effects, and the mechanical response under cyclic loading remain insufficiently addressed. To bridge this gap, this paper proposes and validates an integrated experimental–numerical framework for the design and mechanical characterization of anti-tetrachiral and hexachiral metallic auxetic structures manufactured by laser cutting, a fabrication technology readily available at the industrial scale. First, finite element analysis models are developed to predict the mechanical response of the auxetic structures and are validated through quasi-static experimental testing. Then, a parametric analysis is performed to quantify the influence of key structural parameters, including ligament thickness and node geometry, on stiffness and deformation behavior. Photoelasticity is introduced as a complementary experimental technique to qualitatively assess stress distribution, providing additional insight beyond numerical simulations. Furthermore, cyclic loading tests are conducted to evaluate the durability and stability of the structures under repeated mechanical loading. The results demonstrate that laser cutting significantly affects mechanical behavior, which enhances elastic response while reducing toughness, highlighting the need for post-process heat treatment in practical applications. The study reveals a degradation of mechanical properties under repeated loading up to the yield point, emphasizing the importance of defining safe cyclic-loading limits. The proposed framework establishes practical design and manufacturing guidelines that support the reliable industrial use of metallic auxetic structures in applications requiring lightweight and mechanically robust components.