Effect of dynamic mechanical parameters on acoustic absorption performance of viscoelastic material under hydrostatic pressure

Abstract Hydroacoustic components experience changes in geometric dimensions and dynamic mechanical parameters under hydrostatic pressure, leading to degradation in their sound absorption performance. This study investigates the influence of dynamic mechanical parameters of viscoelastic materials on the sound absorption characteristics of specimens. By establishing a conversion model between mechanical and acoustic parameters for homogeneous viscoelastic materials using longitudinal wave velocity as bridging parameters, we predict sound absorption performance through dynamic mechanical parameters. The effects of Young’s modulus, loss factor, Poisson’s ratio, and other dynamic mechanical parameters on sound absorption are systematically analyzed. Finite element (FE) simulations validate the accuracy of the conversion model, explore the combined influence of multiple varying dynamic mechanical parameters on sound absorption, and investigate the mechanisms by which these parameters influence the sound absorption properties of viscoelastic materials through calculations of total power dissipation density. A direct wave extraction method is employed to measure the dynamic mechanical parameters of a viscoelastic material under different hydrostatic pressures. The fitted curves of measurement results are incorporated into FE simulation models to calculate the sound absorption coefficients under varying pressures. Finally, experiment in a water-filled acoustic tube showed that the simulated and experimental absorption coefficients closely matched across all pressure conditions. These results validate the effectiveness of both the theoretical model and the FE simulation model. This study presents a reliable approach for predicting the acoustic performance of viscoelastic materials under varying hydrostatic pressures.