Parametric study of a metaporous made of solid inclusions embedded in a rigid frame porous material glued on a rigid backing

摘要

With the growing interest for sound absorbing materials, research is brought to optimizeporous material whose acoustic absorption coefficient should to remain large across abroad frequency range. Embedding rigid inclusions in a porous plate can enhance itsacoustical properties and create an efficient sound insulating material for low frequencies.The excitation of additional acoustic modes when periodic arrangements of inclusions areused can lead to enhanced acoustic energy dissipation due to the viscous and thermaleffects in the material pores when the wavelength is comparable with the radius of theinclusions.By acting on the characteristics of individual cells (periodicity, shape, type ...), it is possibleto combine absorption related to the medium with additional resonant effects at lowfrequencies.A parametric study is performed in order to determine the influence of the geometry,orientation and resonance frequency of infinitely rigid inclusions embedded in a porousplate. The behavior of these structured materials is computed by finite element method todetermine the 'optimal' inclusion in order to obtain an efficient absorbing material.