Results 111 to 120 of about 456 (152)
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Journal of Science and Technique, 2021
This paper presents a simulation-based model for predicting the acoustic properties of underwater anechoic structures with its main layer made of viscoelastic sound absorbing materials including air-filled cavities. Some preliminary numerical results are first compared with the published analytical and experimental data to validate the proposed ...
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This paper presents a simulation-based model for predicting the acoustic properties of underwater anechoic structures with its main layer made of viscoelastic sound absorbing materials including air-filled cavities. Some preliminary numerical results are first compared with the published analytical and experimental data to validate the proposed ...
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A Wide Band Strong Acoustic Absorption in a Locally Network Anechoic Coating
Chinese Physics Letters, 2009Composite materials with interpenetrating network structures usually exhibit unexpected merit due to the cooperative interaction. Locally resonant phononic crystals (LRPC) exhibit excellent sound attenuation performance based on a periodical arrangement of sound wave scatters.
Jiang Heng +5 more
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Tunable underwater sound absorption characteristics of 0–3 piezoelectric anechoic coating
The Journal of the Acoustical Society of AmericaPiezoelectric composite materials (PCMs) with shunt damping circuits are used widely in hydroacoustics because of the flexible adjustability of their parameters. PCMs offer good underwater sound absorption, but shortcomings remain, such as poor low-frequency sound absorption, narrow bandwidth, and a single dissipation mechanism.
Xinyu Jia +4 more
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Numerical design of Alberich anechoic coatings with superellipsoidal cavities of mixed sizes
The Journal of the Acoustical Society of America, 2008Thin rubber coatings with cavities in a doubly periodic lattice are able to reduce reflections of underwater sound by redistributing normally incident energy such that absorption in the surrounding rubber is enhanced. For spherical scatterers, the anechoic effect can be studied numerically by the layer multiple-scattering method.
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Research on a Design Method of Generative Model for Cavity Section Shape of an Anechoic Coating
Advances in Engineering Technology Research, 2023One of the main challenges of the low frequency, broadband and strong sound absorption performance of an anechoic coating is the design of the cavity section shape. A generative-based design method was investigated in this study. Two generative-based models were trained to design the cavity section shape of anechoic coatings with a highly efficient ...
Yiping Sun, Meng Tao
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Performance study of preliminary mini anechoic chamber fitted with coconut shell coated absorbers
2013 IEEE International Conference on Control System, Computing and Engineering, 2013An anechoic chamber is considered good when there is no signal reflection inside the chamber and also when there is no incoming signal from outside the chamber. The key element inside an anechoic chamber is the absorbing material. The evaluations of mini anechoic chamber fitted with coated absorbers were carried out by analyzing the absorption ...
Hasnain Abdullah +11 more
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Anechoic coatings obtained from two- and three-dimensional monopole resonance diffraction gratings
The Journal of the Acoustical Society of America, 2012Underwater sound reflections can be reduced in magnitude by a rubber coating including three-dimensional (3-D) cavities forming a doubly periodic diffraction grating. A monopole resonance for sphere-like cavities enhances absorption in the surrounding rubber solid.
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Journal of Sound and Vibration, 2018
Abstract Rubbery coatings embedded with air cavities are commonly used on underwater structures to reduce reflection of incoming sound waves. In this paper, the relationships between Poisson's and modulus loss factors of rubbery materials are theoretically derived, the different effects of the tiny Poisson's loss factor on characterizing the loss ...
Jie Zhong +4 more
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Abstract Rubbery coatings embedded with air cavities are commonly used on underwater structures to reduce reflection of incoming sound waves. In this paper, the relationships between Poisson's and modulus loss factors of rubbery materials are theoretically derived, the different effects of the tiny Poisson's loss factor on characterizing the loss ...
Jie Zhong +4 more
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The Journal of the Acoustical Society of America, 2014
Global optimization methods can be used to numerically determine optimal design parameters for an object. However, this does not by itself give a good appreciation of other parameter choices that may be almost as good and even preferable from other points of view.
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Global optimization methods can be used to numerically determine optimal design parameters for an object. However, this does not by itself give a good appreciation of other parameter choices that may be almost as good and even preferable from other points of view.
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Note on the validity of using plane-wave type relations to characterize Alberich anechoic coatings
The Journal of the Acoustical Society of America, 1992The efficiency of echo reduction due to the coating of a rigid plane structure by a properly designed material can be determined via the measurement of the reflection and transmission coefficients of a panel made up with this material using a simple, plane-wave type relation.
Anne-Christine Hladky-Hennion +1 more
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