TY  - JOUR
SP  - 126
UR  - http://doi.org/10.1016/j.ijsolstr.2016.01.005
JF  - International Journal of Solids and Structures
N2  - A simplified model of periodic chiral beam-lattices containing local resonators has been formulated to obtain a better understanding of the influence of the chirality and of the dynamic characteristics of the local resonators on the acoustic behaviour. The beam-lattice models are made up of a periodic array of rigid heavy rings, each one connected to the others through elastic slender massless ligaments and containing an internal resonator made of a rigid disk in a soft elastic annulus. The band structure and the occurrence of low frequency band-gaps are analysed through a discrete Lagrangian model. For both the hexa- and the tetrachiral lattice, two acoustic modes and four optical modes are identified and the influence of the dynamic characteristics of the resonator on those branches is analysed together with some properties of the band structure. By approximating the ring displacements of the discrete Lagrangian model as a continuum field and through an application of the generalized macro-homogeneity condition, a generalized micropolar equivalent continuum has been derived, together with the overall equation of motion and the constitutive equation given in closed form. The validity limits of the dispersion functions provided by the micropolar model are assessed by a comparison with those obtained by the discrete model.
A1  - Bacigalupo, Andrea
A1  - Gambarotta, Luigi
ID  - eprints3784
EP  - 141
PB  - Elsevier
Y1  - 2016///
AV  - public
KW  - Chiral lattice; Metamaterials; Local resonator; Band gaps; Floquet?Bloch spectrum; Dispersive waves
VL  - 83
SN  - 0020-7683
TI  - Simplified modelling of chiral lattice materials with local resonators
ER  -