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Negative mass sound shielding structures: Early results
Author(s) -
Calius Emilio P.,
Bremaud Xavier,
Smith Bryan,
Hall Andrew
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200982040
Subject(s) - electromagnetic shielding , resonator , vibration , electrical impedance , materials science , negative mass , finite element method , acoustics , work (physics) , effective mass (spring–mass system) , acoustic impedance , mechanics , frequency band , computational physics , physics , structural engineering , composite material , classical mechanics , engineering , telecommunications , thermodynamics , optoelectronics , bandwidth (computing) , quantum mechanics
Elastic meta‐materials or meta‐composites can be designed to have a negative effective mass density at certain vibration frequencies, thus blocking wave propagation through the material within that frequency band. The negative mass behaviour is generated by resonant structures within the material that oscillate 180° out of phase with the acoustic pressure waves applied to the surface. As this research is in its initial stages this paper describes work in progress in both the experimental and numerical domains, and some early results from solids containing geometrically simple spring–mass resonant structures. Behaviour is characterized experimentally by dynamic tests of individual resonators as well as impedance tube measurements of panel‐like structures containing multiple resonant elements. The experimental results exhibit clear evidence of the expected resonances, and partial band gap behaviour. Finite element models of both single resonant elements and impedance tube specimens are being developed, and the current status of these models is described. Their results to date show good agreement with the mass law and qualitative agreement with the experimental results.