Abstract
Enhancements in manufacturing technologies, especially 3D-printing, have enabled the production of intricate micro-scale, elastic meta-structures. This study explores the broadband vibration absorption characteristics of these structures for three different geometries: simple-cubic periodic geometries as well as the more-involved diamond and octet-truss micro-lattice geometries. Broadband absorption is experimentally achieved for the basic cubic geometries with band gaps approximately 3000 Hz in width. A band gap of 3500 Hz is found in the octet-truss lattice with a 5% mass increase. The diamond lattice achieves a band gap width which doubles its cubic counterparts (6500 Hz), but only at a cost of a 4% mass increase. We compare the experimental findings to the theoretical results obtained by modeling the structure as a discrete, lumped mass system and employing modal analysis and transfer-function matrix methods. These comparisons show a mismatch between the theoretical and the experimental frequency responses. This mismatch is attributed to the inconsistencies inherent to 3D-printing processes, and to the need for more accurate modeling of the lattice structures.
