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MECSOL 2022
8th International Symposium on Solid Mechanics
Optimization of Vibration Band Gaps in Damped Elastic Metamaterials
Submission Author:
Rubens Gonçalves Salsa Junior , RN
Co-Authors:
Rubens Gonçalves Salsa Junior, Thiago de Paula Sales, Domingos Rade
Presenter: Rubens Gonçalves Salsa Junior
doi://10.26678/ABCM.MECSOL2022.MSL22-0014
Abstract
In structural dynamics, the band gap phenomena has been extensively researched as means to reduce vibration transmission in elastic metamaterials. For non-dissipative structures, band gaps can be obtained from the dispersion relation and they are associated with frequency ranges where no propagating wave modes exist. The presence of damping makes this approach inconvenient to determine band gaps because all wave modes exhibit attenuation. Since some level of damping is unavoidable in real structures, it is necessary to include dissipation to improve the predictability of the mathematical models. In this regard, the main objective of this work is to obtain an optimal design of a damped three-dimensional elastic meta-structure. This meta-structure was modeled by the finite elements method and wave modes were obtained by taking into account Floquet-Bloch boundary conditions. Band gaps were identified with an evanescence index and the dependence of the band gaps of the investigated lattice structure on design parameters was duly analyzed. Throughout the text, the main differences in optimization procedure between a damped and undamped structure are highlighted. It has been verified that the optimal damped meta-structure has wider range of attenuation than the undamped optimal one, but with decreased peak of attenuation. At last, the optimization procedure was validated numerically for a finite structure, which demonstrated reduced transmissibility of bending, longitudinal and torsional motions. This demonstrates the potential utility of this elastic meta-structure in diverse applications requiring vibration suppression.
Keywords
elastic metamaterials, periodic structures, phonic crystals, band gaps, Optimization, damping
