Sound Transmission Through Simply Supported Finite Double-Panel Partitions With Enclosed Air Cavity

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
F. X. Xin ◽  
T. J. Lu ◽  
C. Q. Chen
Keyword(s):  
Sound Velocity ◽  
Velocity Potential ◽  
Transmission Loss ◽  
Elevation Angle ◽  
Sound Transmission ◽  
Double Fourier Series ◽  
Potential Method ◽  
Air Cavity ◽  
Simply Supported ◽  
Physical Mechanisms

The vibro-acoustic performance of a rectangular double-panel partition with enclosed air cavity and simply mounted on an infinite acoustic rigid baffle is investigated analytically. The sound velocity potential method rather than the commonly used cavity modal function method is employed, which possesses good expandability and has significant implications for further vibro-acoustic investigations. The simply supported boundary condition is accounted for by using the method of modal function and the double Fourier series solutions are obtained to characterize the vibro-acoustic behaviors of the structure. The results for sound transmission loss, panel vibration level, and sound pressure level are presented to explore the physical mechanisms of sound energy penetration across the finite double-panel partition. Specifically, focus is placed on the influence of several key system parameters on sound transmission including the thickness of air cavity, structural dimensions, and the elevation angle and azimuth angle of the incidence sound. Further extensions of the sound velocity potential method to typical framed double-panel structures are also proposed.

SOUND TRANSMISSION ACROSS A FINITE SIMPLY SUPPORTED DOUBLE-LAMINATED COMPOSITE PLATE WITH ENCLOSED AIR CAVITY

2019 ◽  
Vol 57 (6) ◽  
pp. 749
Author(s):  
Pham Ngoc Thanh ◽  
Tran Ich Thinh
Keyword(s):  
Boundary Conditions ◽  
Composite Plate ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Laminated Composite ◽  
Acoustic Vibration ◽  
Potential Method ◽  
Laminated Composite Plate ◽  
Air Cavity ◽  
Simply Supported

ABSTRACTSound transmission across a finite orthotropic laminated double-composite plate with enclosed air cavity on an infinite acoustic rigid baffle is investigated analytically. Sound velocity potential method combined with simply supported boundary conditions is used instead of traditional methods, has good scalability and is important for studies of acoustic vibration of structures. The sound transmission loss is calculated from the ratio of incident to transmitted acoustic powers. Specifically, the focus is placed on the effects of several key system parameters on sound transmission including the plate dimensions, the laminate configurations, the boundary conditions, and the composite materials are systematically examined.

Acoustic performance prediction of a multilayered finite cylinder equipped with porous foam media

2020 ◽  
Vol 26 (11-12) ◽  
pp. 899-912 ◽  
Author(s):  
Hamed Darvish Gohari ◽  
MohamdReza Zarastvand ◽  
Roohollah Talebitooti
Keyword(s):  
Transmission Loss ◽  
Shear Deformation Theory ◽  
Sound Transmission ◽  
Double Fourier Series ◽  
Finite Cylinder ◽  
Sound Insulation ◽  
Transverse Displacement ◽  
Sound Transmission Loss ◽  
Insulation Property ◽  
Longitudinal Modes

This paper presents an analytical model to embed porous materials in a finite cylindrical shell in order to obtain the sound transmission loss coefficient. Although the circumferential modes are considered only for calculating the amount of the transmitted noise through an infinitely long cylinder, the present study employs the longitudinal modes in addition to circumferential ones to analyze the vibroacoustic performance of a simply supported cylinder subjected to the porous core based on the first order shear deformation theory. To achieve this goal, the structure is immersed in a fluid and excited by an acoustic wave. In addition, the acoustic pressures and the displacements are developed in the form of double Fourier series. Since these series consist of infinite modes, it is essential to terminate this process by considering adequate modes. Hence, the convergence checking algorithm is employed in the form of some three-dimensional configurations with respect to length, frequency and radius. Afterwards, some figures are plotted to confirm the accuracy of the present formulation. In these configurations, the obtained sound transmission loss from the present study is compared with that of the infinite one. It is shown that by increasing the length of the structure, the results are approached to sound transmission loss of the infinite shells. Moreover, a new approach is proposed to show the transverse displacement of a finite poroelastic cylinder at different frequencies. Based on the outcomes, it is found that by enhancing the length of the poroelastic cylinder, the amount of the transmitted sound into the structure is reduced at the high frequency domain. However, the sound insulation property of the structure is improved at the low frequency region when the radius of the shell is decreased.

Sound transmission loss of double plates with an air cavity between them in a rigid duct

2016 ◽  
Vol 139 (5) ◽  
pp. 2324-2333 ◽  
Author(s):  
Hyun-Sil Kim ◽  
Sang-Ryul Kim ◽  
Seong-Hyun Lee ◽  
Yun-Ho Seo ◽  
Pyung-Sik Ma
Keyword(s):  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Air Cavity

Sound transmission loss characteristics of four-side simply supported sandwich panels

2017 ◽  
Vol 21 (2) ◽  
pp. 707-726 ◽  
Author(s):  
Wei Li ◽  
Yansong He ◽  
Zhongming Xu ◽  
Zhifei Zhang
Keyword(s):  
Natural Frequencies ◽  
Transmission Loss ◽  
Flexural Rigidity ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
High Accuracy ◽  
Face Sheet ◽  
Sound Transmission Loss ◽  
Simply Supported ◽  
The Face

In this study, a theoretical investigation on the sound transmission loss characteristics of four-side simply supported sandwich panels considering the flexural rigidity of the face sheet has been presented. With the flexural rigidity of the face sheet taken into account, the sound transmission problem of the sandwich panels is derived from the governing equation of bending vibration. The sound transmission loss expression is also derived. The validation of the theoretical prediction model is validated by comparing with the high-accuracy finite element and boundary element simulation. Numerical analysis shows that the flexural rigidity of face sheet influences the natural frequencies obviously, and the theoretical prediction model proposed has high accuracy on predicting the natural frequencies and sound transmission loss of four-side simply supported sandwich panels. The effects of the face sheet flexural rigidity, the thickness of face sheets and core layer, as well as the damping coefficient of the core on the sound transmission loss are systematically investigated.

Sound transmission through a stiff double-panel structure periodically stabilized by negative stiffness module: Theoretical modeling

2020 ◽  
Vol 26 (23-24) ◽  
pp. 2286-2296 ◽  
Author(s):  
Akintoye O Oyelade
Keyword(s):  
Transmission Loss ◽  
Virtual Work ◽  
Elevation Angle ◽  
Low Frequency ◽  
Sound Transmission ◽  
Negative Stiffness ◽  
Negative Element ◽  
Space Harmonics ◽  
Model Predictions ◽  
Analytic Expressions

Analytic expressions are derived for models predicting the influence of periodically spaced structural links on sound transmission through a double-panel structure. The double panel has been configured to have two sets of structural links: a rib stiffener and negative stiffness component. The stiffener is identical and is spaced periodically at a distance. However, the negative element component is shifted by an amount q from the other set. The dynamic equation of the vibroacoustic of the system is formulated in terms of the space harmonics and by the principle of virtual work. The model is validated by comparing the model predictions with the existing result from the literature. Then, influences of the negative element, engineering safety, offset, and elevation angle are investigated. A new antiresonance with a huge sound transmission loss value can be engineered at the low-frequency region when these parameters are varied. In addition, the application of the stiff model is implemented for a periodic acoustic metamaterial structure. The negative stiffness inclusion can prevent wave propagation at low frequency. The periodic structure can be designed to obtain more and wider frequency bandgaps.

scholarly journals Vibroacoustic analysis of a clamped finite orthotropic laminated double-composite plate with an air cavity

2019 ◽  
Author(s):  
Tran Ich Thinh ◽  
Pham Ngoc Thanh
Keyword(s):  
Composite Plate ◽  
Series Solution ◽  
Transmission Loss ◽  
Plate Theory ◽  
Laminated Composite ◽  
Double Fourier Series ◽  
Laminated Plate ◽  
Laminated Composite Plate ◽  
Air Cavity ◽  
Theoretical Results

The vibroacoustic analysis of a clamped finite orthotropic laminated double-composite plate with a closed air cavity is investigated analytically presented within classical laminated plate theory for laminated composite plate. Using the method of modal decomposition, a double Fourier series solution is obtained to characterize the vibroacoustic performance of the structure. The sound transmission loss (STL) is calculated from the ratio of incident to transmitted acoustic powers. The accuracy of the solution is shown with comparing the STL values obtained from this presented model with the experimental and theoretical results available in literature. The soundproof ability of finite double-composite plate with a clamed boundary is shown. The effects of thickness of faceplates, thickness of air cavity and the angles of the incident sound are systematically examined.

scholarly journals Array Gain of a Linear Array in an Ocean Waveguide

2021 ◽  
Vol 11 (11) ◽  
pp. 5046
Author(s):  
Zong-Wei Liu ◽  
Chun-Mei Yang ◽  
Ying Jiang ◽  
Lei Xie ◽  
Jin-Yan Du ◽  
...  
Keyword(s):  
Transmission Loss ◽  
Spatial Coherence ◽  
Correlation Coefficients ◽  
Channel Correlation ◽  
Acoustic Channel ◽  
Physical Mechanisms ◽  
Channel Characteristics ◽  
Special Case ◽  
Array Gain ◽  
Insight Into

Array gain is investigated based on the acoustic channel characteristics manifested by the fluctuant transmission loss and decrease in the acoustic channel spatial coherence. An analytical expression is derived as the summation of the products of the acoustic channel correlation coefficients and root-mean-square pressures. The formula provides insight into the physical mechanisms of the gain degradation in the ocean waveguide. Furthermore, this formula provides a new method to study array gain in the ocean waveguide from underwater acoustic field. The obtained expression is a more general formula that is applicable to shallow water, deep sea, and continental slope, with the traditional methods as a special case. Numerical results show that the array gain calculated by previous formulas are generally overestimated, caused by ignoring the effect of transmission loss fluctuation.

scholarly journals Analysis of the transmission loss of double-leaf panels with an equivalent spring–mass model for studs

2020 ◽  
Vol 37 ◽  
pp. 126-133
Author(s):  
Yuan-Wei Li ◽  
Chao-Nan Wang
Keyword(s):  
Distribution Curve ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Experimental Results ◽  
Sound Insulation ◽  
Sound Transmission Loss ◽  
Mass Model ◽  
Steel Stud ◽  
Panel Thickness ◽  
Stiffness Distribution

Abstract The purpose of this study was to investigate the sound insulation of double-leaf panels. In practice, double-leaf panels require a stud between two surface panels. To simplify the analysis, a stud was modeled as a spring and mass. Studies have indicated that the stiffness of the equivalent spring is not a constant and varies with the frequency of sound. Therefore, a frequency-dependent stiffness curve was used to model the effect of the stud to analyze the sound insulation of a double-leaf panel. First, the sound transmission loss of a panel reported by Halliwell was used to fit the results of this study to determine the stiffness of the distribution curve. With this stiffness distribution of steel stud, some previous proposed panels are also analyzed and are compared to the experimental results in the literature. The agreement is good. Finally, the effects of parameters, such as the thickness and density of the panel, thickness of the stud and spacing of the stud, on the sound insulation of double-leaf panels were analyzed.

Sign in / Sign up

Export Citation Format

Share Document