Experimental observations of the main hypothesis employed in the definition of the wTCM finite element under compression

Auxetic metamaterials, characterized by their negative Poisson’s ratio, offer unique mechanical properties such as enhanced energy absorption, improved indentation resistance, and high shear stiffness, making them promising candidates for advanced engineering applications. This work presents experimental and numerical analyses of a 3D-printed coupon based on the General Auxetic Metamaterial (GAM) cell. A quasi-static compression test was performed to validate the auxetic behavior and to characterize the deformation and failure mechanisms. In parallel, an innovative multiscale finite element methodology based on the wTCM element was applied to replicate the mechanical response of the structure with significantly reduced computational cost. The results demonstrate strong agreement between experimental observations and numerical predictions in terms of global auxetic response, axial force-displacement behavior, and local failure modes. Once properly calibrated, the methodology enables accurate prediction of volumes with different sizes and geometries, thereby reducing the need for extensive experimental campaigns and enabling the efficient simulation of large-scale metamaterial structures.