Mechanical stabilization of filament-printed fibrous metamaterials via novel hinge architectures

Fibrous metamaterials derive their macroscopic mechanical response from the interplay between fiber deformation and hinge mechanics. This work introduces a novel printable hinge conception for filament-based additive manufacturing that is designed to behave as a perfect pivot and to improve structural stability under compression. Experiments on specimens subjected to bias-extension and compression tests show that the proposed hinges preserve the characteristic second-gradient response of fibrous metamaterials while contributing to delay the onset of transverse instability (qualitative evidence). The improved compressive behavior suggests potential applications in lightweight fibrous composite metamaterials requiring enhanced stability and deformation control. A second-gradient continuum model is calibrated against the experimental bias-extension response and used to perform finite element based numerical simulations. The resulting simulations reproduce the experimental force–displacement behavior with very good accuracy, supporting both the effectiveness of the proposed hinge design and the relevance of the adopted higher-order continuum description.