Prediction of Sound Transmission Loss for Finite Sandwich Panels Based on a Test Procedure on Beam Elements

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Zhongchang Qian ◽  
Daoqing Chang ◽  
Bilong Liu ◽  
Ke Liu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Test Procedure ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Expansion Method ◽  
Bending Stiffness ◽  
Sound Transmission Loss ◽  
Modal Expansion ◽  
Beam Elements

An approach on the prediction of sound transmission loss for a finite sandwich panel with honeycomb core is described in the paper. The sandwich panel is treated as orthotropic and the apparent bending stiffness in two principal directions is estimated by means of simple tests on beam elements cut from the sandwich panel. Utilizing orthotropic panel theory, together with the obtained bending stiffness in two directions, the sound transmission loss of simply-supported sandwich panel is predicted by the modal expansion method. Simulation results indicated that dimension, orthotropy, and loss factor may play important roles on sound transmission loss of sandwich panel. The predicted transmission loss is compared with measured data and the agreement is reasonable. This approach may provide an efficient tool to predict the sound transmission loss of finite sandwich panels.

Sound transmission loss characteristics of sandwich aircraft panels: Influence of nature of core

2016 ◽  
Vol 19 (1) ◽  
pp. 26-48 ◽  
Author(s):  
MP Arunkumar ◽  
Jeyaraj Pitchaimani ◽  
KV Gangadharan ◽  
MC Lenin Babu
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sheet Material ◽  
Low Frequency ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Honeycomb Core ◽  
Transmission Characteristics ◽  
The Impact

Sandwich panel which has a design involving acoustic comfort is always denser and larger in size than the design involving mechanical strength. The respective short come can be solved by exploring the impact of core geometry on sound transmission characteristics of sandwich panels. In this aspect, the present work focuses on the study of influence of core geometry on sound transmission characteristics of sandwich panels which are commonly used as aircraft structures. Numerical investigation has been carried out based on a 2D model with equivalent elastic properties. The present study has found that, for a honeycomb core sandwich panel in due consideration to space constraint, better sound transmission characteristics can be achieved with lower core height. It is observed that, for a honeycomb core sandwich panel, one can select cell size as the parameter to reduce the weight with out affecting the sound transmission loss. Triangular core sandwich panel can be used for low frequency application due to its increased transmission loss. In foam core sandwich panel, it is noticed that the effect of face sheet material on sound transmission loss is significant and this can be controlled by varying the density of foam.

Predicting the Sound Transmission Loss of Sandwich Panels by Statistical Energy Analysis Approach

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
Tongan Wang ◽  
Shan Li ◽  
Shankar Rajaram ◽  
Steven R. Nutt
Keyword(s):  
Sandwich Panel ◽  
Energy Analysis ◽  
Transmission Loss ◽  
Plate Theory ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Present Approach ◽  
Statistical Energy Analysis ◽  
Sound Transmission Loss ◽  
Wave Numbers

A statistical energy analysis (SEA) approach is used to predict the sound transmission loss (STL) of sandwich panels numerically. Unlike conventional SEA studies of the STL of sandwich panels, which consider only the antisymmetric (bending) motion of the sandwich panel, the present approach accounts for both antisymmetric and symmetric (dilatational) motions. Using the consistent higher-order sandwich plate theory, the wave numbers of the waves propagating in the sandwich panel were calculated. Using these wave numbers, the wave speed of the propagating waves, the modal density, and the radiation efficiency of the sandwich panels were determined. Finally, the sound transmission losses of two sandwich panels were calculated and compared with the experimentally measured values, as well as with conventional SEA predictions. The comparisons with the experimental data showed good agreement, and the superiority of the present approach relative to other approaches is discussed and analyzed.

Sound transmission loss behavior of sandwich panel with different truss cores under external mean airflow

2019 ◽  
Vol 86 ◽  
pp. 714-723 ◽  
Author(s):  
Tao Fu ◽  
Zhaobo Chen ◽  
Hongying Yu ◽  
Xuezhi Zhu ◽  
Yanzheng Zhao
Keyword(s):  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss

Predicting the Sound Transmission Loss of Honeycomb Panels using the Wave Propagation Approach

2011 ◽  
Vol 97 (5) ◽  
pp. 869-876 ◽  
Author(s):  
Sathish Kumar ◽  
Leping Feng ◽  
Ulf Orrenius
Keyword(s):  
Wave Propagation ◽  
Transmission Loss ◽  
Plate Theory ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Structural Vibration ◽  
Sound Transmission Loss ◽  
Resonance Frequencies ◽  
Fluid Coupling ◽  
Vibration And Sound Radiation

The sound transmission properties of sandwich panels can be predicted with sufficient degree of accuracy by calculating the wave propagation properties of the structure. This method works well for sandwich panels with isotropic cores but applications to panels with anisotropic cores are hard to find. Honeycomb is an example of anisotropic material which when used as a core, results in a sandwich panel with anisotropic properties. In this paper, honeycomb panels are treated as being orthotropic and the wavenumbers are calculated for the two principle directions. These calculated wavenumbers are validated with the measured wavenumbers estimated from the resonance frequencies of freely hanging honeycomb beams. A combination of wave propagation and standard orthotropic plate theory is used to predict the sound transmission loss of honeycomb panels. These predictions are validated through sound transmission measurements. Passive damping treatment is a common way to reduce structural vibration and sound radiation, but they often have little effect on sound transmission. Visco-elastic damping with a constraining layer is applied to two honeycomb panels with standard and enhanced fluid coupling properties. This enhanced fluid coupling in one of the test panels is due to an extended coincidence range observed from the dispersion curves. The influence of damping treatments on the sound transmission loss of these panels is investigated. Results show that, after the damping treatment, the sound transmission loss of an acoustically bad panel and a normal panel are very similar.

scholarly journals Analytical Study on the Rate of Sound Transmission Loss in Single Row Honeycomb Sandwich Panel Using a Numerical Method

2020 ◽  
Vol 54 (2) ◽  
pp. 127-137
Author(s):  
Rohollah Fallah Madvari ◽  
Mohammad Reza Monazzam ◽  
Mohsen Niknam Sharak and Mohsen Mosa Farkhani
Keyword(s):  
Numerical Method ◽  
Analytical Study ◽  
Sandwich Panel ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Single Row ◽  
Honeycomb Sandwich
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