Speaker
Description
In recent years, metamaterials have received a great deal of research attention due to their potential for energy dissipation. Their ability to finely tune critical modes and to harness non-Eulerian instability mechanisms (such as snap-through) opens the way to substantial energy absorption while preserving elastic reversibility. Remarkably, these dynamic and dissipative characteristics are not intrinsic but can be precisely engineered through deliberate manipulation of the material microgeometry.
In this work, a metamaterial featuring generic rigid finite-sized joints has been investigated. The lattice is represented as a grid of shearable and flexible beams interconnected by rigid components and, by employing Bloch-Floquet theory, the closed-form expression of the stability domain and the associated critical modes have been analytically derived. By suitably selecting the geometric parameters of the rigid joints, it becomes possible to tailor a broad spectrum of critical modes under different macro-stress states, enabling the onset of microscopic critical modes before the macroscopic ones. It is emphasized that, in this metamaterial, chirality influences only the micro-critical state, while leaving the macro critical state unaffected. The analytical findings have been subsequently compared with FEM simulations and experimental tests conducted on 3D-printed specimens, revealing a good level of agreement.
References
[1] Marasciuolo, N., De Tommasi, D., Trentadue, F., Vitucci, G., Tailored multiscale instabilities in a grid metamaterial, Extreme Mechanics Letters, 75, 102284, 2025.
[2] Trentadue, F., Caramia, G., De Tommasi, D., Marasciuolo, N., Vitucci, G., Elastic stability of a lattice of cross-braced shear deformable beams, European Journal of Mechanics-A/Solids, 102, 105118, 2023.
[3] Trentadue, F., De Tommasi, D., Marasciuolo, N., Stability domain and design of a plane metamaterial made up of a periodic mesh of rods with cross-bracing cables, Applications in Engineering Science, 5, 100036, 2021.