Lattice metamaterials enable control of wave propagation and vibration mitigation through the tailored design of their internal geometry. Most modeling approaches rely on the assumption of perfect regular geometry, while real structures fabricated via additive manufacturing actually exhibit geometric imperfections. Understanding how such deviations affect mechanical behavior and wave attenuation mechanisms is essential for the development of the reliable design of architected materials [1]. This work aims at investigating the dynamic response of 3D printed lattice structures by systematically comparing ideal and fabricated metamaterials. The study focuses on one dimensional beam-like lattices obtained by the repetition of selected two-dimensional unit cells (UC), analyzing how different geometric configurations, i.e. UC shape and their arrangement, influence the dispersion properties and the resulting attenuation behavior. Ideal periodic geometries are analyzed using Bloch-Floquet theory to compute dispersion relations and identify band gap regions. To account for manufacturing induced imperfections, finite element models of lattice specimens based on real geometries are developed. Frequency response functions are computed for finite structures, enabling a direct assessment of wave attenuation in the presence of weak geometric disorder. An experimental campaign is conducted on specimens manufactured in thermoplastic polyurethane (TPU) via fused deposition modelling. Experimental measurements are used to extract attenuation curves and validate the numerical predictions [2]. The results show that weak but distributed geometric imperfections significantly influence the dynamic behavior of lattice metamaterials, emphasizing the importance of accounting for manufacturing effects already at the design phase [3]. REFERENCES [1] L. Parente, D. Addessi, P. Di Re, C. Gatta, E. Sacco, 2025. Micromechanical buckling analysis of soft lattice metamaterials accounting for randomly distributed imperfections. Mechanics Research Communications. [2] S. Timorian, M. Ouisse, S. De Rosa, F. Franco, 2020, Numerical investigations and experimental measurements on the structural dynamic behaviour of quasi-periodic meta-materials. Mechanical Systems and Signal Processing. [3] Y. Li, R. Cottereau, B. Tie, 2024, A Bloch analysis extended to weakly disordered periodic media. Journal of Sound and Vibration.