scholarly journals Locally resonant metamaterial curved double wall to improve sound insulation at the ring frequency and mass-spring-mass resonance

2021 ◽  
Vol 149 ◽  
pp. 107179 ◽  
Author(s):  
Zibo Liu ◽  
Romain Rumpler ◽  
Leping Feng
Keyword(s):  
Sound Insulation ◽  
Mass Spring ◽  
Double Wall ◽  
Ring Frequency

Influence of Perforated Ceiling on Floor Impact Sound Insulation in Reinforced Concrete Buildings

2019 ◽  
Vol 105 (5) ◽  
pp. 727-731
Author(s):  
Inho Kim ◽  
Jongkwan Ryu ◽  
Sungchan Lee
Keyword(s):  
Reinforced Concrete ◽  
Sound Insulation ◽  
Light Weight ◽  
Reinforced Concrete Buildings ◽  
Mass System ◽  
Rubber Ball ◽  
Absorption Area ◽  
Weight Impact ◽  
Single Number ◽  
Mass Spring

In this study, the influence of a perforated ceiling on the floor impact sound was investigated. The floor impact sound measurements were conducted both with and without suspended ceiling including the perforated and nonperforated panel, using heavy and light weight impact sources in a reinforced concrete test building. The results indicated that the perforated ceiling with and without absorption sheet greatly reduced the resonance of floor impact sound by the non-perforated ceiling. However, the perforated ceiling without an absorption sheet did not improve the single number quantity (SNQ, rubber ball: L′iA,Fmax,V.T and tapping machine: L′n,w) for the floor impact sound insulation. The perforated ceiling with attached absorption sheet produced SNQs of 2 dB lower and higher than that produced by the non-perforated ceiling for heavy and light weight impact sources, respectively. It was also found that the improvement in the floor impact sound insulation after the installation of the perforated ceiling was related to the mass-spring-mass system, rather than the absorption area of the receiving room.

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.

Low Frequency Acoustic Performance of Close-Fitting Sandwich Panels

1998 ◽  
Vol 5 (3) ◽  
pp. 143-161 ◽  
Author(s):  
W.C. Tang ◽  
C.F. Ng
Keyword(s):  
Porous Material ◽  
Low Frequency ◽  
Coupled System ◽  
Sound Insulation ◽  
Flexible Plate ◽  
Cavity Depth ◽  
Acoustic Cavity ◽  
Air Cavities ◽  
Rigid Walls ◽  
Double Wall

The experiment presented in this paper was to investigate and analyse the noise reduction at low frequency of porous material used to line the cavity between two panels of a double-panel structure. The effects of panel construction, fibreglass and cavity depth have also been studied. The structural-acoustic coupled system of a sandwich structure, backed by a rectangular acoustic cavity of rigid walls is discussed. It is found that the sound insulation of a combination of a stiff thick and a thin flexible plate panel, with air cavities and porous material in-between, is more effective than that of the conventional double-wall panel at low frequency.

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.

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.

Simulation and Analysis of Two-Mass Suspension Modification Using MATLAB Programming

2019 ◽  
Vol 3 (1) ◽  
pp. 160-165
Author(s):  
Hendry D. Chahyadi
Keyword(s):  
Vibrational Energy ◽  
State Space Model ◽  
Mass System ◽  
Modeling And Analysis ◽  
The Road ◽  
Final Project ◽  
Quarter Car ◽  
Automotive Suspension ◽  
Mass Spring ◽  
Matlab Programming

The designs of automotive suspension system are aiming to avoid vibration generated by road condition interference to the driver. This final project is about a quarter car modeling with simulation modeling and analysis of Two-Mass modeling. Both existing and new modeling are being compared with additional spring in the sprung mass system. MATLAB program is developed to analyze using a state space model. The program developed here can be used for analyzing models of cars and vehicles with 2DOF. The quarter car modelling is basically a mass spring damping system with the car serving as the mass, the suspension coil as the spring, and the shock absorber as the damper. The existing modeling is well-known model for simulating vehicle suspension performance. The spring performs the role of supporting the static weight of the vehicle while the damper helps in dissipating the vibrational energy and limiting the input from the road that is transmitted to the vehicle. The performance of modified modelling by adding extra spring in the sprung mass system provides more comfort to the driver. Later on this project there will be comparison graphic which the output is resulting on the higher level of damping system efficiency that leads to the riding quality.

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