Colombi et al., JASAEL (2015)

In this paper we investigate numerically the possibility offers by an ensemble of long aluminum rods coupled to a metallic plate to obtain a cloak for elastic waves. This is of great interest in geophysics to protect monuments from seisms. Using the rods as a cloak is motivated by previous studies which shows the possibility to obtain very large hybridization bandgaps explained by the strong coupling of the compressional resonances of the rods with the flexural A0 Lamb wave in the plate.

Then we played on the shape of the cloak (Fig.1b) by adjusting the length of the rods arranged on concentric circles. The Figs.2-3 shows the directivity pattern of two particular cloaks. On the left panels no backward scattered energy is observed.