Transmission loss of a steel noise barrier coated with vibration damping material

1979 ◽  
Vol 65 (S1) ◽  
pp. S65-S65 ◽  
Author(s):  
A. Behar ◽  
D. N. May
Keyword(s):  
Transmission Loss ◽  
Vibration Damping ◽  
Damping Material ◽  
Noise Barrier

Acoustic meta-silencer: Toward enabling ultrawide-band air-permeable noise barrier

2021 ◽  
pp. 107754632110011
Author(s):  
Mohammad Javad Khodaei ◽  
Amin Mehrvarz ◽  
Reza Ghaffarivardavagh ◽  
Nader Jalili
Keyword(s):  
Heat Transfer ◽  
Design Methodology ◽  
Heat Transfer Performance ◽  
Transmission Loss ◽  
Design Parameters ◽  
Transfer Performance ◽  
Noise Mitigation ◽  
Acoustic Cavity ◽  
Road Map ◽  
Noise Barrier

In this article, we have first presented a metasurface design methodology by coupling the acoustic cavity to the coiled channel. The geometrical design parameters in this structure are subsequently studied both analytically and numerically to identify a road map for silencer design. Next, upon tuning the design parameters, we have introduced an air-permeable noise barrier capable of sound silencing in the ultrawide band of the frequency. It is has been shown that the presented metasurface can achieve +10 dB sound transmission loss from 170 Hz to 1330 Hz (≈3 octaves). Furthermore, we have numerically studied the ventilation and heat transfer performance of the designed metasurface. Enabling noise mitigation by leveraging the proposed metasurface opens up new possibilities ranging from residential and office noise reduction to enabling ultralow noise fan, propellers, and machinery.

Preparation of modified polyvinyl formal vibration‐damping material and its application in strawberry

2021 ◽  
Author(s):  
Yiqin Zhang ◽  
Honglei Mu ◽  
Haiyan Gao ◽  
Hangjun Chen ◽  
Weijie Wu ◽  
...  
Keyword(s):  
Vibration Damping ◽  
Polyvinyl Formal ◽  
Damping Material

The Application of BESO in Vibration Damping of Ship Plate

2013 ◽  
Vol 572 ◽  
pp. 185-188 ◽  
Author(s):  
Xiao Yan Teng ◽  
Jia Shan Han ◽  
Liang Peng
Keyword(s):  
Natural Vibration ◽  
Target Function ◽  
Vibration Damping ◽  
Natural Vibration Frequency ◽  
Constraint Condition ◽  
Evolutionary Structural Optimization ◽  
Damping Material ◽  
Reasonable Result ◽  
Beso Method ◽  
Original Amount

Based on the bi-directional evolutionary structural optimization (BESO), the method of determining the adhesion position of the damping material is proposed in this paper, which is applicable to the vibration damping of ship plate. In this method, the needed amount of damping material is taken as the constraint condition, and the maximization of one natural vibration frequency of the structure is taken as the target function. A thin plate structure with both ends constraints has been taken as an example to get the best topology structure of its adhesion damper by taking the BESO method. The result of optimization shows that it still meets the damping requirements when the needed amount of damping material decreases by about 50% of the original amount. The reasonable result demonstrates the effectiveness and engineering value of the method.

Topology Optimization of Carbon Nanotube Reinforced Damping Layers

Aerospace ◽  
2005 ◽  
Author(s):  
Arnold Lumsdaine ◽  
Mohan Damu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Topology Optimization ◽  
Polymer Matrix ◽  
Vibration Damping ◽  
Constrained Layer Damping ◽  
Damping Properties ◽  
Reinforced Polymers ◽  
Damping Material ◽  
Layer Structures

Topology optimization has been successfully used for improving vibration damping in constrained layer damping structures with viscoelastic materials. Reinforcing carbon nanotubes in a polymer matrix greatly influences the mechanical properties of the polymer. Such nanotube-reinforced polymers (NRP) can be used to further enhance the damping properties of the constrained layer structures. The inclusion of nanotubes into a polymer matrix provides a new design variable in the topology optimization studies on such structures. In this work, the topology optimization of structures using such NRP as the damping material is performed. The resulting structures show a phenomenal improvement in damping. Moreover, a more efficient method is used for the optimization process.

scholarly journals Normal Incidence of Sound Transmission Loss of a Double-Leaf Partition Inserted with a Microperforated Panel

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. Putra ◽  
A. Y. Ismail ◽  
R. Ramlan ◽  
Md. R. Ayob ◽  
M. S. Py
Keyword(s):  
Mathematical Model ◽  
Transmission Loss ◽  
Low Frequency ◽  
Sound Transmission ◽  
Normal Incidence ◽  
Sound Transmission Loss ◽  
Engineering Structures ◽  
Air Mass ◽  
Noise Barrier ◽  
The Mathematical Model

A double-leaf partition in engineering structures has been widely applied for its advantages, that is, in terms of its mechanical strength as well as its lightweight property. In noise control, the double-leaf also serves as an effective noise barrier. Unfortunately at low frequency, the sound transmission loss reduces significantly due to the coupling between the panels and the air between them. This paper studies the effect of a microperforated panel (MPP) inserted inside a double-leaf partition on the sound transmission loss performance of the system. The MPP insertion is proposed to provide a hygienic double-leaf noise insulator replacing the classical abrasive porous materials between the panels. It is found that the transmission loss improves at the troublesome mass-air-mass resonant frequency if the MPP is located closer to the solid panel. The mathematical model is derived for normal incidence of acoustic loading.

Study on the Vibro-Acoustic Characteristics of a Vibration Isolation Mass Structure with Composite Braces

2011 ◽  
Vol 117-119 ◽  
pp. 85-88
Author(s):  
Di Jia ◽  
Fu Zhen Pang ◽  
Xu Chao Yin ◽  
Ye Xi
Keyword(s):  
Vibration Isolation ◽  
Transmission Loss ◽  
Flexural Wave ◽  
Acoustic Characteristics ◽  
Damping Material ◽  
Section Size ◽  
Vibration And Sound Radiation ◽  
Vibration Isolation Performance ◽  
Isolation Performance ◽  
Material Study

In this paper a vibration isolation mass structure with composite braces is proposed to reduce noise and vibration transmission through the hull and internals of a double cylindrical shell. Influence of the various complicating effects such as vibration isolation mass’s cross section size or the layout location on the vibration isolation performance of composite braces structure are discussed. Besides, we also provide a composite structure form with high transmission loss due to the theory of vibration insulation of isolation mass and noise reduction of damping material. Study shows that composite braces structure combined the appropriate vibration isolation mass with viscoelastic material can effectively decrease the hull vibration and sound radiation in the mid-high frequency domain, which can significantly attenuate transmission of the plate flexural wave.

Viscoelastic Vibration Damping Materials for Application in a Temperature Range above 150°C

2017 ◽  
Vol 730 ◽  
pp. 569-573 ◽  
Author(s):  
Wen Fei Wang ◽  
Xin Zhi Lin ◽  
Yu Liang Ma
Keyword(s):  
High Temperature ◽  
Bulk Material ◽  
Vibration Damping ◽  
Temperature Range ◽  
Polymer Resin ◽  
Young’S Moduli ◽  
Damping Material ◽  
Viscoelastic Damping Material ◽  
New Type ◽  
Damping Materials

We demonstrate a new type of viscoelastic vibration damping material with high damping performances (tan δ=E′/E′′ ≥0.3 where E′ and E′′ are the storage and loss Young’s moduli, respectively) at a high temperature range between 200°C and 250°C utilizing a special polymer resin of higher glass transition temperature corresponding to the application temperature range and larger pendant groups offering higher efficiency of the energy dissipation. In addition, the damping property of the bulk material reinforced with glass fiber will be significantly improved, where the peak tan δ value can reach 0.7. In this paper, we put the emphasis on the preparation process and properties characterization of this new type material, and try to provide a new method to fabricate a viscoelastic damping material (VDM) usable for applications in the field of high temperature vibration reduction, in contrast to the conventional ones whose damping properties will dramatically decay once the ambient temperature is above 100°C.

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