Optimization and experimental validation of anti-tri chiral lattice metamaterial for broadband vibration suppression

Abstract

A key challenge in metamaterials design is to optimize the anti-tri chiral structure with precise and controllable geometry, considering performance criteria. This work proposes a parametric anti-tri chiral lattice made from Polylactic acid (PLA) polymer to open the wide bandgap for vibration suppression. Experiments and theoretical methods study anti-tri chiral lattice to analyze the vibration attenuation features of the metamaterial. The band structure was studied in terms of the geometry parameters of the unit cell to investigate the effect of geometry changes on the bandgap size. To ensure the best geometry of the anti-tri chiral unit cell, an automated optimization process is conducted using MATLAB and COMSOL Multiphysics based on Non-dominated Sorting Genetic Algorithm II (NSGA-II). Two optimization cases were performed with different objectives, and the results indicated that the optimized geometry yields enhanced vibration suppression capabilities and a wide complete bandgap. Finally, the anti-tri chiral lattice is fabricated using Fused Deposition Molding (FDM), and experimental testing is performed to validate the proposed design.