Vibro-acoustic response and sound transmission loss analysis of functionally graded plates

2014 ◽  
Vol 333 (22) ◽  
pp. 5786-5802 ◽  
Author(s):  
N. Chandra ◽  
S. Raja ◽  
K.V. Nagendra Gopal
Keyword(s):  
Transmission Loss ◽  
Sound Transmission ◽  
Functionally Graded ◽  
Sound Transmission Loss ◽  
Functionally Graded Plates ◽  
Acoustic Response ◽  
Loss Analysis

Functionally graded viscoelastic core characteristics on vibroacoustic behavior of double-walled cylindrical shells in a subsonic external flow

2022 ◽  
pp. 107754632110467
Author(s):  
Shohreh Reaei ◽  
Roohollah Talebitooti
Keyword(s):  
Cylindrical Shell ◽  
Transmission Loss ◽  
Excitation Frequency ◽  
Shear Deformation Theory ◽  
Sound Transmission ◽  
Functionally Graded ◽  
Loss Coefficient ◽  
Sound Transmission Loss ◽  
Polymeric Foam ◽  
The Core

The present study is concerned with an analytical solution for calculating sound transmission loss through an infinite double-walled circular cylindrical shell with two isotropic skins and a polymeric foam core. Accordingly, the two-walled cylindrical shell is stimulated applying an acoustic oblique plane wave. The equations of motion are derived according to Hamilton’s principle using the first-order shear deformation theory for every three layers of the construction. Additionally, by the aid of employing the Zener mathematical model for the core of polymeric foam, mechanical properties are determined. To authenticate the results of this study, the damping of the core layer goes to zero. Therefore, the numerical results in this special case are compared with those of isotropic shells. The results prove that the presented model has high accuracy. It is also designated that decreasing the power-law exponent of the core leads to improving the sound transmission loss through the thickness of the construction. Besides, in addition to probe some configurations versus alterations of frequencies and dimensions, the convergence algorithm is provided. Consequently, it is realized that by increasing the excitation frequency, the minimum number of modes to find the convergence conditions is enhanced. The results also contain a comparison between the sound transmission loss coefficient for four different models of a core of a sandwiched cylindrical shell. It is comprehended that the presented model has a transmission loss coefficient more than the other types of the core at high frequencies.

On the Variability of the Sound Transmission Loss of Composite Panels Through a Parametric Probabilistic Approach

2016 ◽  
Vol 24 (01) ◽  
pp. 1550018 ◽  
Author(s):  
M. A. Ben Souf ◽  
D. Chronopoulos ◽  
M. Ichchou ◽  
O. Bareille ◽  
M. Haddar
Keyword(s):  
Transmission Loss ◽  
Probabilistic Approach ◽  
Sound Transmission ◽  
Wave Mode ◽  
Composite Panel ◽  
Mode Shapes ◽  
Composite Panels ◽  
Sound Transmission Loss ◽  
Acoustic Response ◽  
Polynomial Eigenvalue Problem

A robust model for the prediction of the variability of the vibro-acoustic response is presented in this paper. The dynamic response of composite panels is treated using a Statistical Energy Analysis (SEA) approach. One of the basic input parameters is the propagating flexural wavenumber of the modeled panel. The Wave Finite Element Method (WFEM) is used to investigate the dispersion characteristics of the layered panel. It is based on the evaluation of the mass and the stiffness matrices of a periodic segment of the structure. A polynomial eigenvalue problem is then formed for calculating the wavenumbers and the wave mode shapes. The main novelty in this paper consists in evaluating the influence of the variability of the mechanical parameters of the composite panel on its vibro-acoustic response, that is on its sound transmission loss (STL). This influence is quantified using the generalized polynomial chaos expansion. The efficiency of the approach is exhibited for isotropic and orthotropic panels.

scholarly journals Optimization of Sound Transmission Loss through a Thin Functionally Graded Material Cylindrical Shell

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Nouri ◽  
Sohrab Astaraki
Keyword(s):  
Cylindrical Shell ◽  
Functionally Graded Material ◽  
Transmission Loss ◽  
Minimum Weight ◽  
Sound Transmission ◽  
Functionally Graded ◽  
Sound Transmission Loss ◽  
Softening Effect ◽  
Important Concern ◽  
Graded Material

The maximizing of sound transmission loss (TL) across a functionally graded material (FGM) cylindrical shell has been conducted using a genetic algorithm (GA). To prevent the softening effect from occurring due to optimization, the objective function is modified based on the first resonant frequency. Optimization is performed over the frequency range 1000–4000 Hz, where the ear is the most sensitive. The weighting constants are chosen here to correspond to an A-weighting scale. Since the weight of the shell structure is an important concern in most applications, the weight of the optimized structure is constrained. Several traditional materials are used and the result shows that optimized shells with aluminum-nickel and aluminum-steel FGM are the most effective at maximizing TL at both stiffness and mass control region, while they have minimum weight.

scholarly journals Sound Transmission Loss Analysis for Laminated Glass and Perspex

2018 ◽  
Vol 429 ◽  
pp. 012008
Author(s):  
W. H. Tan ◽  
E. A. Lim ◽  
E. M. Cheng ◽  
K. S. Basaruddin ◽  
M. Hafifi Ramli
Keyword(s):  
Transmission Loss ◽  
Sound Transmission ◽  
Laminated Glass ◽  
Sound Transmission Loss ◽  
Loss Analysis
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