This article presents the static analysis of auxetic beams using a dimensional reduction method applicable to arbitrary cross-section geometries and material anisotropy. The proposed methodology employs equivalent orthotropic properties of an auxetic structure, which expands the field of analyzing advanced composite beams, to those comprising auxetic structures as cores or layers. This article systematically evaluates the verification and fidelity of these elastic properties used in auxetic beam analysis. Various strip, sandwich, and box-beams are assessed. This analysis benefits from an isogeometric-based dimensional reduction method in which the 3D elastic beam problem, comprising auxetic structures, is decomposed into a 2D cross-sectional analysis and a 1D beam model which considerably reduces the numerical cost with good agreement to the finite element estimation. The results are compared with finite element analysis and show that higher unit cell density improves accuracy. Increasing the inclination angle and strip thickness enhances the estimation. The influence of auxetic cell orientation is investigated for sandwich beam with auxetic core. The findings highlight both the limitations and the practical applications of equivalent elastic properties in auxetic beam analysis. This approach provides a simple yet effective framework for designing and analyzing novel composite beams enhanced by auxetic structures.

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