Matryoshka Locally Resonant Sonic Crystal

D. P. Elford, L. Chalmers, F. V. Kusmartsev, and G. M. Swallowe
Department of Physics
Loughborough University
Loughborough, UK

The results of numerical modelling of sonic crystals with resonant array elements are reported. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been identified.

For low frequency broadband attenuation a most optimal configuration is the Matryoshka sonic crystal. This system forms numerous gaps in the lower frequency regime, below Bragg bands, whilst maintaining a reduced crystal size viable for noise barrier technology. The finding opens new perspectives for construction of sound barriers in the low frequency range usually inaccessible by traditional means including conventional sonic crystals.