Global sensitivity analysis of sound attenuation in double-wall system with porous layer

Abstract

This paper investigates the acoustic performance of a double-wall system with a porous layer and presents a global sensitivity analysis of sound attenuation. The transfer matrix method is first applied to predict sound transmission through the structure. This method offers a relatively simple and cost-effective way to model the complex acoustic interactions in these systems and provides rich high-frequency information. The method represents sound wave propagation for each layer using a transfer matrix that depends on the thickness and physical characteristics of each material, and interface matrices are introduced to consider boundary conditions between adjacent layers. The poroelastic layer is modeled using the Biot-Allard approach with nine parameters. Then a global sensitivity analysis is performed using Morris and Sobol methods to identify the parameters that have a significant impact on sound transmission loss. The Morris method is used first to eliminate the parameters that have the least impact, and the Sobol method is then employed to analyze the remaining parameters and their interactions in more detail. The study focuses on eleven parameters, including all the physical parameters of the foam, and thicknesses of plates, cavity, and foam. The results of the sensitivity analysis indicate that geometrical parameters such as the thickness of different layers have the most significant impact on the sound transmission loss response in the lower frequency range. In contrast, foam properties such as flow resistivity have more influence in the higher frequency range. Overall, this study is the first to apply sensitivity analysis methods to the problem of sound transmission through double wall systems with porous layers, providing valuable insights into the system’s behavior and its design optimization.