Prediction method of sound absorption properties of porous materials by probabilistic homogenization method using perturbation method

Abstract

Quantitative evaluation of uncertainty in acoustic properties is an essential issue to improve product quality. The acoustic properties of porous materials, such as sound absorption coefficient, are affected by variations in microstructure and material properties during manufacturing. In particular, the microstructure uncertainty significantly affects the variation of the sound absorption coefficient, and a trial-and-error approach using prototypes is necessary for its evaluation. This study proposes a method to obtain the probability distribution of the sound absorption coefficient by combining the homogenization method with the probabilistic approach under the microstructure uncertainty. Defining the porosity and the homologous deformation of the unit structure as random variables, the probability distribution of the sound absorption coefficient was calculated using the homogenization method and the Monte Carlo simulation or perturbation method. The result by the perturbation agrees well with the Monte Carlo simulation result, and the uncertainty of the sound absorption coefficient can be evaluated with our proposed method. Using the method developed in this study, the effect of microstructure variation on the sound absorption properties of porous materials by simulation can be predicted. Our method can contribute to the development of new sound-absorbing materials.

Keywords

• sound absorption coefficient
• poroelastic material
• homogenization
• multiscale
• optimization
• perturbation