An equivalent method for predicting acoustic scattering of coated shell using identified viscoelastic parameters of anechoic coating. (August 2021)

• Record Type: Journal Article
• Authors: Ke, Yibo; Zhang, Lin; Zhao, Xuefeng; Tao, Meng
• Is Part Of: Applied acoustics. Volume 179(2021)
• Publication Date: 2021-08
• Subjects: Anechoic coating -- Viscoelastic parameters -- Identification method -- Acoustic scattering -- Equivalent method; Acoustical engineering -- Periodicals; Periodicals; 620.2
• DOI: 10.1016/j.apacoust.2021.108071
• Languages: English
• ISSNs: 0003-682X

Abstract

Highlights: A method to identify the viscoelastic parameters of underwater anechoic coating. An equivalent method of a perforated coating approximated to be a homogenous and solid coating. Using the equivalent homogenous coating to predict acoustic scattering performance of coated elastic shell efficiently. Abstract: A novel method to identify the viscoelastic parameters of underwater anechoic coating has been proposed in this present study. Based on two sets of measured reflection coefficients, the viscoelastic parameters can be identified by using the combination of finite element method and Newton's iterative method. The identification method is used to obtain the viscoelastic parameters of polyurethane, and the effects of some experimental errors, including the mismatched amplitude responses and the mismatched phase responses of two hydrophones on the identified results are discussed. Then, an equivalent method is developed to predict the acoustic scattering performance of coated shell. The equivalence kernel is that the equivalent coating has the same reflection coefficient as the original perforated anechoic coating by using the genetic algorithm. In order to verify the accuracy of equivalent method, a direct finite element model (perforated coating – spherical shell) for acoustic scattering simulation is precisely modelled, where the material of coating is selected to be the identified polyurethane. Obtained results are compared to the acoustic scattering of equivalent method (homogenous coating – spherical shell). Good agreement between two models shows that the equivalent method is feasible and effective to predict the acoustic scattering of coated shell. Moreover, it is found that applying the equivalent method greatly reduces the computational expenses compared to the conventional direct model.