scholarly journals Comparative Study of Sound Transmission Losses of Sandwich Composite Double Panel Walls

2020 ◽  
Vol 10 (4) ◽  
pp. 1543 ◽  
Author(s):  
Chukwuemeke William Isaac ◽  
Marek Pawelczyk ◽  
Stanislaw Wrona
Keyword(s):  
Composite Structures ◽  
Transmission Loss ◽  
Optimization Problems ◽  
Sound Transmission ◽  
Industrial Applications ◽  
Sandwich Composite ◽  
Acoustic Response ◽  
Transmission Losses ◽  
Emission Index ◽  
Selection Of

The increasing motivation behind the recently wide industrial applications of sandwich and composite double panel structures stems from their ability to absorb sounds more effectively. Meticulous selection of the geometrical and material constituents of both the core and panels of these structures can produce highly desirable properties. A good understanding of their vibro-acoustic response and emission index such as the sound transmission loss (STL) is, therefore, a requisite to producing optimal design. In this study, an overview of recent advances in STL of sandwich and composites double panels is presented. At first, some salient explanation of the various frequency and controlled regions are given. It then critically examines a number of parameter effects on the STL of sandwich and composite structures. Literatures on the numerical, analytical and experimental solutions of STL are systematically presented. Efficient and more reliable optimization problems that maximize the STL and minimize the objective functions capable of degrading the effectiveness of the structure to absorb sounds are also provided.

scholarly journals Design, Manufacturing, and Characterization of Hybrid Carbon/Hemp Sandwich Panels

2021 ◽  
Author(s):  
Luca Boccarusso ◽  
Fulvio Pinto ◽  
Stefano Cuomo ◽  
Dario De Fazio ◽  
Kostas Myronidis ◽  
...  
Keyword(s):  
Composite Structures ◽  
Failure Modes ◽  
Sandwich Panels ◽  
Industrial Applications ◽  
Low Velocity Impact ◽  
Sandwich Composite ◽  
Continuous Manufacturing ◽  
Low Velocity ◽  
Impact Compression

AbstractAdvanced sandwich composite structures that incorporate foams or honeycombs as core materials, have been extensively investigated and used in various applications. One of the major limitations of the conventional materials used is their weak impact resistance and their end-of-life recyclability and overall sustainability. This paper is focused on the study of the production and mechanical characterization of hybrid sandwich panels using hemp bi-grid cores that were manufactured with an ad hoc continuous manufacturing process. Bi-grid structures were stratified in multiple layers, resulting in cores with different thicknesses and planar density. Sandwich panels made with carbon fibers skins were then subjected to Low Velocity Impact, compression and indentation and the damaged panels were investigated via CT-Scan. Results show that the high tailorability of the failure modes and the very good energy absorption properties of the hybrid material open new exciting perspectives for the development of new sandwich structures that can extend the use of natural fibers into several industrial applications.

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 Ultralight Graphene Oxide/Polyvinyl Alcohol aerogel for broadband and tuneable acoustic properties

2021 ◽  
Author(s):  
Mario Rapisarda ◽  
Gian-Piero Malfense Fierro ◽  
Michele Meo
Keyword(s):  
Graphene Oxide ◽  
Polyvinyl Alcohol ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Acoustic Properties ◽  
Low Density ◽  
Transmission Losses ◽  
New Class ◽  
Processing Times

Abstract An ultralight Graphene Oxide/Polyvinyl Alcohol (GO/PVA) aerogel is proposed as a new class of acoustic materials with tuneable and broadband sound absorption and transmission loss. The interaction between GO sheets and PVA molecules are exploited in our environmentally friendly manufacturing process to fabricate aerogels with hierarchical and tuneable porosity embedded in a honeycomb scaffolding. The developed aerogels show an enhanced dissipation of sound energy, with an extremely low density of 2.10 kg m-3 , one of the lowest values ever reported for acoustic materials. We have first experimentally evaluated and optimized the effects of composition and thickness on the acoustic properties, namely sound absorption and sound transmission losses. Subsequently, we have employed a semi-analytical approach to evaluate the effect of different processing times and find the relationships between the acoustic and non-acoustic properties of the materials. Over the 400 – 2500 Hz range, the reported average sound absorption coefficients are as high as 0.79 for low density aerogels, while the average sound transmission losses can reach 15.8 dB for higher density aerogels. We envision our subwavelength aerogel-based design, tailored at achieving optimal acoustic performance, as a novel lightweight material for advanced engineering applications.

The transmission loss through curved sandwich composite structures

2004 ◽  
Vol 115 (5) ◽  
pp. 2537-2537
Author(s):  
Sebastian Ghinet ◽  
Noureddine Atalla ◽  
Haisam Osman
Keyword(s):  
Composite Structures ◽  
Transmission Loss ◽  
Sandwich Composite

Source levels and communication-range models for harp seal (Pagophilus groenlandicus) underwater calls in the Gulf of St. Lawrence, Canada

2009 ◽  
Vol 87 (7) ◽  
pp. 609-617 ◽  
Author(s):  
M. A. Rossong ◽  
J. M. Terhune
Keyword(s):  
Background Noise ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Transmission Losses ◽  
Sea State ◽  
Mean Values ◽  
Communication Range ◽  
Pagophilus Groenlandicus ◽  
Hydrophone Array

Harp seals ( Pagophilus groenlandicus (Erxleben, 1777)) produce underwater call types during the breeding season that are thought to be important for reproductive behaviours and herd formation. Underwater calls were recorded in the Gulf of St. Lawrence, Canada, in March 2007. A four hydrophone array system determined the locations of nearby calling seals and call source levels (amplitudes at 1 m from the seal). Source levels ranged from 103 to 180 dB re 1 µPa-m and mean values per call type ranged from 129 to 151 dB re 1 µPa-m with considerable overlap between call types. Short-range sound transmission losses under the ice were variable. Theoretical communication-range models were constructed under quiet (0 sea state, transmission-loss pattern of 20 log range) and noisy (herd noise, transmission-loss patterns of 15, 17.5, or 20 log range) conditions. Monte Carlo models for the calls for a quiet sea indicated median distances of 0.5–5.5 km (maximum 80 km). Communication distances in the presence of other calling seals dropped to 0.03–0.5 km (maximum 15 km) for dB loss = 20 log range but were longer under different spreading-loss patterns. Communication ranges are significantly influenced by call source levels, background noise, and in situ sound transmission patterns.

Structural-Acoustic Optimization of Sandwich Panels

2006 ◽  
Vol 129 (3) ◽  
pp. 330-340 ◽  
Author(s):  
Francesco Franco ◽  
Kenneth A. Cunefare ◽  
Massimo Ruzzene
Keyword(s):  
Composite Structures ◽  
Sandwich Panels ◽  
Structural Elements ◽  
Acoustic Response ◽  
Truss Core ◽  
Design Flexibility ◽  
Radiated Sound ◽  
Optimal Configurations ◽  
Selection Of ◽  
Radiated Sound Power

Sandwich panels comprising face sheets enclosing a core are increasingly common structural elements in a variety of applications, including aircraft fuselages, flight surfaces, vehicle panels, lightweight enclosures, and bulkheads. This paper presents the optimization of various innovative sandwich configurations for minimization of their structural-acoustic response. Laminated face sheets and core geometries comprising honeycomb and trusslike structures are considered. The design flexibility associated with the class of considered composite structures and with truss-core configurations provides the opportunity of tailoring the structure to the load and dynamic response requirements of a particular application. The results demonstrate how the proper selection of selected key parameters can achieve effective reduction of the radiated sound power and how the identified optimal configurations can achieve noise reduction over different frequency ranges and for various source configurations.

scholarly journals Sound Transmission Loss Analysis on Building Materials

2018 ◽  
Vol 15 (4) ◽  
pp. 6001-6011 ◽  
Author(s):  
Tan Wei Hong ◽  
C. F. Sin
Keyword(s):  
Building Materials ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Expanded Polystyrene ◽  
Sound Insulation ◽  
Insulation Material ◽  
Sound Transmission Loss ◽  
Loss Analysis ◽  
Aerated Concrete ◽  
Selection Of

This study is mainly to determine the sound transmission loss (STL) performance of the four selected building materials using the impedance tube. The four building materials are; autoclaved aerated concrete (AAC), laminated glass, expanded polystyrene and rockwool. Transmission loss occurs when a sound goes through a partition or barrier. The specimens are prepared in two thicknesses, which are 10 mm and 20 mm. The STL of the specimen was determined and analysed. It is observed that the STL results for all the tested materials are having a similar trend, which is a thicker specimen gives higher STL. In general, all the materials deliver high STL at the frequency range of 3000 – 5500 Hz. In overall, the result shows that the expanded polystyrene scores the highest STL among the four building materials in this study. Six combinations of different material also were tested, and AAC & expanded polystyrene combination shows the highest STL value among the six combinations. The outcomes of this study can be referred by noise control engineer on the selection of the sound insulation material for the building noise insulation treatment.

scholarly journals Sound Transmission Loss of a Metal Panel With Rib Reinforcements and Pasted Damping

2020 ◽  
Vol 25 (4) ◽  
pp. 513-524
Author(s):  
Xin-Xing Xie ◽  
Zhong-Xiang Yuan ◽  
Wen-Bin Shangguan
Keyword(s):  
Experimental Method ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Processing Technique ◽  
Calculation Model ◽  
Simulation Approach ◽  
Transmission Losses ◽  
Damping Material ◽  
Proposed Model ◽  
Data Processing Technique

The sound transmission losses (STL) of a metal panel with rib reinforcement (MPRR) are studied by both an experimental method and a simulation approach. The experimental method and data processing technique for obtaining STL are presented. Six MPRRs with different number of rib reinforcement and different geometry size of rib reinforcement, and six MPRRs with different type of the pasted damping material are designed and anufactured, and their STL performances are investigated by experimental method. The calculation model for STL of a MPRR is proposed and the calculated STL are compared favorably with the experimental data, which validates the proposed model. The analytical methods and conclusions are instructive for the design and the tuning of STL of MPRRs.

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