%0 Report
%9 Working Paper
%A Bacigalupo, Andrea
%A Lepidi, Marco
%A Gnecco, Giorgio
%A Gambarotta, Luigi
%D 2015
%F eprints:3120
%I IMT Institute for Advanced Studies Lucca
%T Optimal design of auxetic hexachiral metamaterials with local resonators
%U http://eprints.imtlucca.it/3120/
%X A parametric beam lattice model is formulated to analyse the propagation properties of elastic in-plane waves in an auxetic material based on a hexachiral topology of the periodic cell, equipped with inertial local resonators. The Floquet-Bloch boundary conditions are imposed on a reduced order linear model in the only dynamically active degrees-offreedom. Since the resonators can be designed to open and shift band gaps, an optimal design, focused on the largest possible gap in the low-frequency range, is achieved by solving a maximization problem in the bounded space of the significant geometrical and mechanical parameters. A local optimized solution, for a the lowest pair of consecutive dispersion curves, is found by employing the globally convergent version of the Method of Moving asymptotes, combined with Monte Carlo and quasi-Monte Carlo multi-start techniques.