閉空間における音圧応答最小化を目的とした吸音材のトポロジー最適化(機械力学,計測,自動制御)

抄録

In this paper, we propose a new topology optimization method to be applied for designing layouts of poroelastic material in an acoustic cavity in order to depress sound pressure levels arising from acoustic resonance. In this method, mean sound pressure levels are minimized utilizing the attenuation of sound by poroelastic material such as sound absorbing material. Biot's theory is incorporated into the optimization scheme to deal with poroelastic material. Air medium contained in the design domain is approximately represented in the expression of Biot's theory. These unified expressions of poroelastic material and air medium by Biot's theory allow to utilize a material interpolation scheme in the density approach of topology optimization. We also propose a new material interpolation scheme that can be applied for poroelastic material. In this scheme, we interpolate several physical quantities such as bulk modulus, densities and porosity that are used in the governing equations of Biot's theory. Several one- and two-dimensional numerical examples are presented to demonstrate that the proposed method can provide clear configurations of poroelastic material that reduce mean sound pressure levels within prescribed evaluation domain for specified frequency ranges.