Abstract
Recent experiments have proved that sonic crystals containing locally resonant structures exhibit strong sound attenuation bands at frequencies about two orders of magnitude smaller than predicted by Bragg’s theory. The effect is well reproduced here by means of two-dimensional numerical simulations of the elastic wave propagation in a 13 cm slab of locally resonant sonic crystals. Three strong attenuation bands are found in the frequency range from 0.3 to 6.0 kHz. A heuristic model is proposed, which allows one to predict the resonance frequencies in good agreement with the numerical simulations.