Sound Transmission Through a Double-Wall Structure Coupled with Two Trapezoidal Acoustic Cavities

2016 ◽  
Vol 08 (08) ◽  
pp. 1650100 ◽  
Author(s):  
Haosen Yang ◽  
Hui Zheng ◽  
Xiang Xie
Keyword(s):  
Theoretical Model ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Sound Insulation ◽  
Wall Structure ◽  
Acoustic System ◽  
Acoustic Cavity ◽  
Acoustic Cavities ◽  
Insulation Performance ◽  
Double Wall

This paper aims at investigating the sound transmission mechanism of a flexibly-linked finite length double-wall structure. The problem stems from the modeling of sound transmission through corrugated core sandwich panels for predicting its transmission loss. The spatial segmentation of the acoustic gap and fully structure-acoustic coupling effect between the flexural vibration of the inclined mechanical link and the two adjacent trapezoidal acoustic cavities are considered. The theoretical model of the considered vibro-acoustic system is developed by using the modal superposition method in conjunction with envelope rectangular technique. Based on the developed theoretical model, the general vibro-acoustics characteristics of the system is presented. Particularly by using the [Formula: see text] mode of the acoustic cavity and the first structural modal frequency, the ratio between the aerostatic stiffness and the structural stiffness is formulated, and a criterion is proposed to determine whether the sound insulation performance of the vibro-acoustic system is controlled mainly by the structure or the acoustic cavity. Numerical investigations reveal that with different stiffness ratio, the acoustic cavity affects the sound transmission through both the added stiffness and added mass following different mechanisms. Besides, the influence of the inclined angle of the connecting beam on sound insulation performance of the double-wall structure is also studied. The obtained results are believed to be helpful in the optimal design of corrugated core sandwich panels for sound insulation.

Reduction of Sound Transmission Through Finite Clamped Metamaterial-Based Double-Wall Sandwich Plates with Poroelastic Cores

2019 ◽  
Vol 105 (5) ◽  
pp. 850-868
Author(s):  
Jingru Li ◽  
Peng Yang ◽  
Sheng Li
Keyword(s):  
Vibration Isolation ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Insulation ◽  
Sandwich Plates ◽  
Low Frequencies ◽  
Finite Structures ◽  
The Galerkin Method ◽  
Insulation Performance ◽  
Double Wall

Finite structures play a more realistic role in applications designed for sound and vibration isolation. Doublepanel structure with poroelastic cores is able to exhibit a superior sound insulation performance in mid-high frequency range, while is relatively inferior to isolate waves at low frequencies. In order to further reduce sound transmission at low frequencies and cater for the actual situation, this paper decides to introduce the metamaterial concept into finite double-wall sandwich plates and presents an analytical model to calculate the sound transmission loss through the metamaterial-based double-panel with fully clamped boundary conditions. The metamaterial-based double-wall sandwich plates are constructed by replacing the bare panel with the metamaterial plate, consisting of a homogeneous plate and periodically attached local resonators. Biot's theory is used to examine the wave propagation in the poroelastic medium. The vibro-acoustic problem of the proposed sandwich plate is solved by employing the modal superposition theory and the Galerkin method. Numerical results show that the sound transmission is significantly reduced at low frequencies. Unique phenomena caused by attached local resonators are explained and the eff ects of resonator inerter, incident angles and damping on the sound insulation properties are also studied.

scholarly journals A Study on the Sound Insulation Performance of Cross-laminated Timber

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4144
Author(s):  
Jui-Yen Lin ◽  
Chieh-Ting Yang ◽  
Yaw-Shyan Tsay
Keyword(s):  
Performance Test ◽  
Prediction Models ◽  
Sound Insulation ◽  
Wall Structure ◽  
Gypsum Board ◽  
Cross Laminated Timber ◽  
Simulation Tools ◽  
Cavity Structure ◽  
Insulation Performance ◽  
Double Wall

Cross-laminated Timber (CLT) has become an emerging board material of wood construction that is strong enough to sustain a high-rise building. However, many wooden congregate housing units overseas that utilize CLT have poor sound environments because the low mass of such wood influences sound insulation performance. In this research, we explored the effect of different CLT walls on sound insulation performance and integrated applicable sound insulation simulation tools to simplify the process of designing a CLT wall structure. This research aimed at a double wall and CLT combined with a gypsum board as the research object. The sound insulation performance test was carried out in a laboratory, while the sound insulation performance of the structure was predicted through simulation tools and prediction models and then compared with the measured values to verify the applicability of the simulation tool. The CLT with a double wall and CLT with gypsum board (CLT + GB) achieved Rw of 50 dB. The numerical simulation had better prediction performance than INSUL at the double wall, while the double wall with cavity structure was close to the measured result via mass law calculation. The INSUL-predicted CLT with a gypsum board at 500 Hz~3150 Hz was close to the measured value.

scholarly journals Sound insulation performance optimization of lightweight sandwich panels

2016 ◽  
Vol 18 (4) ◽  
pp. 2574-2586 ◽  
Author(s):  
Xiao-mei Xu ◽  
Yi-ping Jiang ◽  
Heow-pueh Lee ◽  
Ning Chen
Keyword(s):  
Performance Optimization ◽  
Sandwich Panels ◽  
Sound Insulation ◽  
Insulation Performance

A Model for the Fast Determination of Modal Sound Transmission of Large Rectangular Opening

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Jiazhu Li ◽  
Rui Zhang ◽  
Shen Chen ◽  
Can Li ◽  
Jian Chen
Keyword(s):  
Wave Equations ◽  
Three Dimensional ◽  
Sound Transmission ◽  
Computational Effort ◽  
Sound Insulation ◽  
Fast Determination ◽  
High Frequencies ◽  
Higher Order Modes ◽  
Insulation Performance

Abstract The existence of openings affects the sound insulation performance of structures significantly. The determination of sound transmission through large rectangular openings is often time-consuming, because of the large number of modes, especially if there is a need to go to high frequencies. A model is proposed and detailed based on three-dimensional wave equations, the transfer matrix method, and modal superposition. The viscous and thermal boundary layer effects have been concerned; hence, the model accuracy for narrow slits was improved. The computational effort is significantly decreased by neglecting the cross-modal sound transmission. The accuracy of this model is validated by comparing it with the existing model, the measurement, and the acoustic finite element method. The study of sound transmission behavior of higher-order modes is performed. The modal sound transmission is predicted and compared for several modes. The phenomenon that is different from that of the plane wave situation is found and discussed.

An improved approach for normal-incidence sound transmission loss measurement using a four-microphone impedance tube

2020 ◽  
pp. 107754632092690
Author(s):  
Zechao Li ◽  
Sizhong Chen ◽  
Zhicheng Wu ◽  
Lin Yang
Keyword(s):  
Transfer Matrix ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Normal Incidence ◽  
Sound Insulation ◽  
Sound Transmission Loss ◽  
The Common ◽  
Wavefield Decomposition ◽  
Insulation Performance

The main aim of this study is to introduce an improved method for determining the sound properties of acoustic materials which is more precise than the common wavefield decomposition method and simpler than the common transfer matrix method. In the first part of the article, a group of formulae for calculating sound transmission loss is represented by combining the wavefield decomposition and transfer matrix methods. Subsequently, a formula for calculating sound absorption coefficients is derived from these formulae by definition. Furthermore, the present formulae are validated by comparing the experimental results achieved with the present formulae and those results obtained by other methods recorded in published articles. Eventually, it is demonstrated that the method can accurately measure the sound insulation performance of materials and the sound absorption properties of limp and lightweight materials.

Impact sound transmission: experiments of control at the receiver room

2021 ◽  
Vol 263 (1) ◽  
pp. 5595-5599
Author(s):  
Davi Akkerman ◽  
Paola Weitbrecht ◽  
Mariana Shieko ◽  
Marcel Borin ◽  
Leonardo Jacomussi
Keyword(s):  
Social Housing ◽  
Sound Transmission ◽  
Field Tests ◽  
Sound Level ◽  
Sound Insulation ◽  
Total Cost ◽  
Acoustic Performance ◽  
The Impact ◽  
Insulation Performance

Considering Impact sound level requirements accomplishment in Brazil, floating floors are still considered as an inviable solution for building companies due to the implications in the total cost of building, mainly for social housing. Alternative and sometimes cheaper solutions are those undertaken in the receiver room. However, the lack of laboratory and field tests on the acoustic performance of this type of system is still a barrier for acoustic designing in Brazil. The aim of this paper is to study and validate different constructive solutions developed jointly with building companies for improving the impact sound insulation performance on the receiving room of new Brazilian housing constructions.

Sound Transmission Loss of Adhesively Bonded Sandwich Panels with Pyramidal Truss Core: Theory and Experiment

2015 ◽  
Vol 07 (01) ◽  
pp. 1550013 ◽  
Author(s):  
C. Shen ◽  
Q. C. Zhang ◽  
S. Q. Chen ◽  
H. Y. Xia ◽  
F. Jin
Keyword(s):  
Adhesive Bonding ◽  
Transmission Loss ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Homogenization Theory ◽  
Sound Insulation ◽  
Sound Transmission Loss ◽  
Adhesively Bonded ◽  
Effective Elastic Constant ◽  
Standing Wave Tube

In this paper, an analytical model is developed to investigate sound transmission loss characteristic of adhesively bonded metal sandwich panels with pyramidal lattice truss cores based on 3D elasticity theory. Meanwhile, practical specimen is fabricated to conduct corresponding sound insulation experiment test via a standing wave tube method. The effective elastic constant of truss cores is derived using one homogenization theory on account of equivalent strain energy. It is found that satisfactory agreement is achieved between theoretical solutions and experiment results, and damping effect of adhesive bonding interface between facesheets and core has a great impact on transmission loss. Further parameter investigations demonstrate the significant effect of the elevation and azimuth angles of the pyramidal cores, which can be conveniently changed to tailor the acoustic performance of the sandwich panels in the whole frequency range.

Sound Insulation Performance of Finite Orthotropic Sandwich Panels

2013 ◽  
Vol 377 ◽  
pp. 12-16 ◽  
Author(s):  
Sheng Chun Wang ◽  
Wei Dong Shen ◽  
Jia Feng Xu ◽  
Pei Wen Wang ◽  
Yun Li
Keyword(s):  
Transmission Loss ◽  
Sandwich Panels ◽  
Sheet Thickness ◽  
Face Sheet ◽  
Sound Insulation ◽  
Honeycomb Sandwich ◽  
Theoretical Predictions ◽  
Core Thickness ◽  
Insulation Performance ◽  
Good Agreement

A theoretical model for calculating sound transmission loss (STL) of finite honeycomb sandwich panels is developed. The accuracy of the theoretical predictions is checked against experimental data, with good agreement achieved. Numerical analysis shows that increasing face sheet thickness can improve STL effectively, which is much more effective than increasing the core thickness. Core thickness and Youngs modulus of face sheet have evident effect on coincidence frequency, which should not be neglected when predicting STL.

scholarly journals Sound Insulation of Corrugated-Core Sandwich Panels: Modeling, Optimization and Experiment

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7785
Author(s):  
Longlong Ren ◽  
Haosen Yang ◽  
Lei Liu ◽  
Chuanlong Zhai ◽  
Yuepeng Song
Keyword(s):  
High Frequency ◽  
Sandwich Panel ◽  
Transmission Loss ◽  
Finite Size ◽  
Sandwich Panels ◽  
Sound Transmission ◽  
Coefficient Of Determination ◽  
Design Parameters ◽  
Sound Insulation ◽  
Vast Number

With the extension of the applications of sandwich panels with corrugated core, sound insulation performance has been a great concern for acoustic comfort design in many industrial fields. This paper presents a numerical and experimental study on the vibro-acoustic optimization of a finite size sandwich panel with corrugated core for maximizing the sound transmission loss. The numerical model is established by using the wave-based method, which shows a great improvement in the computational efficiency comparing to the finite element method. Constrained by the fundamental frequency and total mass, the optimization is performed by using a genetic algorithm in three different frequency bands. According to the optimization results, the frequency averaged sound transmission of the optimized models in the low, middle, and high-frequency ranges has increased, respectively, by 7.6 dB, 7.9 dB, and 11.7 dB compared to the baseline model. Benefiting from the vast number of the evolution samples, the correlation between the structural design parameters and the sound transmission characteristics is analyzed by introducing the coefficient of determination, which gives the variation of the importance of each design parameter in different frequency ranges. Finally, for validation purposes, a sound insulation test is conducted to validate the optimization results in the high-frequency range, which proves the feasibility of the optimization method in the practical engineering design of the sandwich panel.

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