Underwater Acoustic Absorption of Composite Anechoic Layers With Inner Holes

Ye, Changzheng; Liu, Xuewei; Xin, Fengxian; Lu, Tian Jian

doi:10.1115/1.4042935

Cited by 11 publications

(5 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the E′ of the PU-based composite increased from E4 to E1, the first absorption peak frequency gradually shifted from about 2 to 8 kHz, and the second absorption peak shifted rightward until it disappeared in the studied frequency. The reason was that the increased E′ enhanced the integral stiffness of the composite, leading to an increase in the resonance frequency [ 34 ]. Meanwhile, the increased E′ improved the peak intensity of the resonance absorption peaks, indicating that a relatively high E′ could bring about an improved sound absorption performance (especially at higher frequencies) [ 35 ].…”

Section: Resultsmentioning

confidence: 99%

“…In addition, the part of the composite that dissipated sound energy was gradually decreased at 7 kHz with the reduction in tanδ from tanδ1 to tanδ4. The results demonstrate that although the increase in tanδ could not affect the overall vibration characteristics of the composite, the stress–strain hysteresis effect became obvious; thus, the energy dissipation capacity of the composite was enhanced [ 23 , 34 ]. In other words, more sound wave energy was converted to internal energy and simultaneously dissipated to overcome internal resistance at the same frequency, resulting in improving sound absorption proprieties.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Finite Element Solution for Dynamic Mechanical Parameter Influence on Underwater Sound Absorption of Polyurethane-Based Composite

Yin

Liu

Wang

et al. 2022

IJMS

View full text Add to dashboard Cite

Underwater noise pollution, mainly emitted by shipping and ocean infrastructure development of human activities, has produced severe environmental impacts on marine species and seabed habitats. In recent years, a polyurethane-based (PU-based) composite with excellent damping performance has been increasingly utilized as underwater sound absorption material by attaching it to equipment surfaces. As one of the key parameters of damping materials, dynamic mechanical parameters are of vital importance to evaluating the viscoelastic damping property and thus influencing the sound absorption performance. Nevertheless, lots of researchers have not checked thoroughly the relationship and the mechanism of the material dynamic mechanical parameters and its sound absorption performance. In this work, a finite element model was fabricated and verified effectively using acoustic pulse tube tests to investigate the aforementioned issues. The influence of the dynamic mechanical parameters on underwater sound absorption performance was systematically studied with the frequency domain to reveal the mechanism and the relationship between damping properties and the sound absorption of the PU-based composite. The results indicate that the internal friction of the molecular segments and the structure stiffness were the two main contributors of the PU-based composite’s consumption of sound energy, and the sound absorption peak and the sound absorption coefficient could be clearly changed by adjusting the dynamic mechanical parameters of the composite. This study will provide helpful guidance to develop the fabrication and engineering applications of the PU-based composite with outstanding underwater sound absorption performance.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Finite Element Solution for Dynamic Mechanical Parameter Influence on Underwater Sound Absorption of Polyurethane-Based Composite

Yin

Liu

Wang

et al. 2022

IJMS

View full text Add to dashboard Cite

show abstract

“…The study of anechoic coatings with periodic holes is then studied as a special case of the generalized TMM developed. In this regard, the difference between the works of Meng, 21 Tao et al, 32 and Ye et al 22,33 are discussed and the results of the present work are compared with these works as well as numerical simulations which are performed using COMSOL. Moreover, the effect of bulk loss factor on echo reduction of coatings with different cavity shapes is evaluated.…”

Section: Introductionmentioning

confidence: 96%

Analytical and numerical study on absorption of viscoelastic multilayers with variable cross section and cavity

Ashrafi

2023

Proceedings of the Institution of Mechanical Engineers, Part C:

View full text Add to dashboard Cite

Polymeric layers or multilayers with air cavities or solid particles have considerable attenuation properties and can be tailored to have acoustic impedance close to water. So, many underwater sound absorbers are made from such multilayer structures. In this work, first, we present a transfer matrix method (TMM) based on force equilibrium to be used for variable cross-section viscoelastic multilayers with cavities. The method can be used for layers with various cavity designs; also, the outer boundary can be conical or any other axisymmetric shape. The formulation is derived for different outer impedance-matched boundary conditions. The study of anechoic coatings with periodic holes is then studied as a special case of the developed TMM. In this regard, the difference between the present formulation and related literature is explained and the TMM results are compared with numerical simulations which are performed using COMSOL. Moreover, the effect of cavity shape and bulk loss factor on the echo reduction properties of the coatings are investigated. It is concluded that for small cavity sizes and with an abrupt change of multilayer cross sections, the echo reduction values are more dependent on bulk loss factor, especially near the resonance frequency.

show abstract

“…Two key requirements for an effective coating design are low sound reflection from the water-coating interface and high sound dissipation within the coating [1][2][3]. A soft material with high shear damping and with an impedance close to the impedance of water is a preferable material candidate as an acoustic coating [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Acoustic Performance of a Metascreen-Based Coating for Maritime Applications

Sharma

Toyoda

Skvortsov

et al. 2022

Journal of Vibration and Acoustics

View full text Add to dashboard Cite

Time and frequency domain numerical models are developed to investigate the acoustic performance of metasurface coatings for marine applications. The coating designs are composed of periodic air-filled cavities embedded in a soft elastic medium, which is attached to a hard backing and submerged in water. Numerical results for a metamaterial coating with cylindrical cavities are favourably compared with analytical and experimental results from the literature. Frequencies associated with peak sound absorption as a function of the geometric parameters of the cavities and material properties of the host medium are predicted. Variation in the cavity dimensions that modifies the cylindrical-shaped cavities to flat disks or thin needles is modelled. Results reveal that high sound absorption occurs when either the diameter or length of the cavities is reduced. Physical mechanisms governing sound absorption for the various cavity designs are described.

show abstract

Underwater Acoustic Absorption of Composite Anechoic Layers With Inner Holes

Cited by 11 publications

References 20 publications

Finite Element Solution for Dynamic Mechanical Parameter Influence on Underwater Sound Absorption of Polyurethane-Based Composite

Finite Element Solution for Dynamic Mechanical Parameter Influence on Underwater Sound Absorption of Polyurethane-Based Composite

Analytical and numerical study on absorption of viscoelastic multilayers with variable cross section and cavity

Acoustic Performance of a Metascreen-Based Coating for Maritime Applications

Contact Info

Product

Resources

About