Autori: Ligia Munteanu, Veturia Chiroiu, Stefania Donescu and Cornel Brisan
Editorial: AIP Publishing, Journal of Applied Physics, 115, p.104904, 2014.
Transformation acoustics opens a new avenue towards the architecture, modeling and simulation of
a new class of sonic composites with scatterers made of various materials and having various
shapes embedded in an epoxy matrix. The design of acoustic scatterers is based on the property of
Helmholtz equations to be invariant under a coordinate transformation, i.e., a specific spatial
compression is equivalent to a new material in a new space. In this paper, the noise suppression for
a wide full band-gap of frequencies is discussed for spherical shell scatterers made of auxetic
materials (materials with negative Poisson’s ratio). The original domain consists of spheres made
from conventional foams with positive Poisson’s ratio. The spatial compression is controlled by the
coordinate transformation, and leads to an equivalent domain filled with an auxetic material. The
coordinate transformation is strongly supported by the manufacturing of auxetics which is based on
the pore size reduction through radial compression molds.
Cuvinte cheie: sonic composites, auxetic material, coordinate transformation