ELFORD, D.P. ... et al, 2010. Acoustic band gap formation in metamaterials. International Journal of Modern Physics B, 24 (25-26), pp. 4935-4945.
We present several new classes of metamaterials and/or locally resonant sonic crystal
that are comprised of complex resonators. The proposed systems consist of multiple
resonating inclusion that correspond to different excitation frequencies. This causes the
formation of multiple overlapped resonance band gaps.We demonstrate theoretically and
experimentally that the individual band gaps achieved, span a far greater range ( 2kHz)
than previously reported cases. The position and width of the band gap is independent
of the crystal’s lattice constant and forms in the low frequency regime significantly below
the conventional Bragg band gap. The broad envelope of individual resonance band gaps
is attractive for sound proofing applications and furthermore the devices can be tailored
to attenuate lower or higher frequency ranges, i.e. from seismic to ultrasonic.