Sound insulation performance of sandwich structure compounded with a resonant acoustic metamaterial

2021 ◽  
pp. 114312
Author(s):  
Qinhao Lin ◽  
Qili Lin ◽  
Yihang Wang ◽  
Guoqing Di
Keyword(s):  
Sandwich Structure ◽  
Sound Insulation ◽  
Acoustic Metamaterial ◽  
Insulation Performance

Low frequency sound insulation performance of asymmetric coupled-membrane acoustic metamaterials

2019 ◽  
Vol 15 (5) ◽  
pp. 1006-1015
Author(s):  
Mengna Cai ◽  
Hongyan Tian ◽  
Haitao Liu ◽  
Yanhui Qie
Keyword(s):  
Low Frequency ◽  
Sound Insulation ◽  
Asymmetric Structure ◽  
Insulation Material ◽  
Metamaterial Structure ◽  
Content Type ◽  
Acoustic Metamaterial ◽  
Frequency Sound ◽  
Membrane Type ◽  
Insulation Performance

Purpose With the development of the modern technology and aerospace industry, the noise pollution is remarkably affecting people’s daily life and has been become a serious issue. Therefore, it is the most important task to develop efficient sound attenuation barriers, especially for the low-frequency audible range. However, low-frequency sound attenuation is usually difficult to achieve for the constraints of the conventional mass-density law of sound transmission. The traditional acoustic materials are reasonably effective at high frequency range. This paper aims to discuss this issue. Design/methodology/approach Membrane-type local resonant acoustic metamaterial is an ideal low-frequency sound insulation material for its structure is simple and lightweight. In this paper, the finite element method is used to study the low-frequency sound insulation performances of the coupled-membrane type acoustic metamaterial (CMAM). It consists of two identical tensioned circular membranes with fixed boundary. The upper membrane is decorated by a rigid platelet attached to the center. The sublayer membrane is attached with two weights, a central rigid platelet and a concentric ring with inner radius e. The influences of the distribution and number of the attached mass, also asymmetric structure on the acoustic attenuation characteristics of the CMAM, are discussed. Findings In this paper, the acoustic performance of asymmetric coupled-membrane metamaterial structure is discussed. The influences of mass number, the symmetric and asymmetry structure on the sound insulation performance are analyzed. It is shown that increasing the number of mass attached on membrane, structure exhibits low-frequency and multi-frequency acoustic insulation phenomenon. Compared with the symmetrical structure, asymmetric structure shows the characteristics of lightweight and multi-frequency sound insulation, and the sound insulation performance can be tuned by adjusting the distribution mode and location of mass blocks. Originality/value Membrane-type local resonant acoustic metamaterial is an ideal low-frequency sound insulation material for its structure is simple and lightweight. How to effectively broaden the acoustic attenuation band at low frequency is still a problem. But most of researchers focus on symmetric structures. In this study, the asymmetric coupled-membrane acoustic metamaterial structure is examined. It is demonstrated that the asymmetric structure has better sound insulation performances than symmetric structure.

scholarly journals Research on the Sound Insulation Properties of Membrane-type Acoustic Metamaterials

2021 ◽  
Vol 252 ◽  
pp. 02028
Author(s):  
Jinyu Hao ◽  
Sheng Guo ◽  
Jian Cheng ◽  
Zhaopin Hu ◽  
Hongyu Cui
Keyword(s):  
Cell Structure ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Acoustic Metamaterials ◽  
Medium Frequency ◽  
Low Frequencies ◽  
Acoustic Metamaterial ◽  
Membrane Type ◽  
Insulation Performance ◽  
Excessive Noise

Low- and medium-frequency noise from ship cabins is difficult to control effectively. Excessive noise can seriously affect the acoustic stealth performance of ships. A novel membrane-type acoustic metamaterial is proposed in this paper with light weight and good sound insulation performance at low frequencies. The sound insulation performance of the metamaterial structure is analysed by using the acoustic-solid coupling module in COMSOL software. Then, the ability to change the sound insulation performance of membrane-type acoustic metamaterials with cell structure and material parameters is obtained. The research results in this paper provide powerful technical support for noise control in ship cabins.

Effect of different types of ceilings on floor impact sound insulation performance in CLT model building

2021 ◽  
Vol 263 (2) ◽  
pp. 4402-4409
Author(s):  
Atsuo Hiramitsu ◽  
Susumu Hirakawa ◽  
Takahiro Tsuchimoto ◽  
Takashi Yamauchi
Keyword(s):  
Model Building ◽  
Sound Insulation ◽  
Impact Noise ◽  
Timber Construction ◽  
Stress Relieving ◽  
Measurement Results ◽  
Absorbing Material ◽  
Vibration Insulator ◽  
Effective Use ◽  
Insulation Performance

The floor impact noise generated in a building often causes problems among residents. The floor impact sound insulation performance of timber construction buildings is lower than that of concrete construction. However, due to the large supply of wood and the stress-relieving effects of wood, the use of wood is being promoted around the world. In Japan, the Act on the Promotion of the Utilization of Wood in Public Buildings was enforced to promote the use of CLT (Cross Laminated Timber) for the effective use of wood. We have been experimentally investigating the effect of floor finish structure in CLT model building. In this paper, we report the measurement results of the change in floor impact sound insulation performance when the suspended ceiling structure was changed. As results, it was confirmed that the effect of the sound-absorbing material in the ceiling cavity and the effect of the double-layer ceiling board were effective. In addition, it was clarified that the dry-type double floor structure with rubber vibration insulator on its legs is an effective floor finish structure for improvement of heavy and light weight floor impact sound insulation performances.

Effect of ceiling and dry-type double floor on heavy-weight floor impact sound in concrete building and CLT building.

2021 ◽  
Vol 263 (3) ◽  
pp. 3064-3072
Author(s):  
Takashi Yamauchi ◽  
Atsuo Hiramitsu ◽  
Susumu Hirakawa
Keyword(s):  
Frequency Band ◽  
Sound Level ◽  
Center Frequency ◽  
Sound Insulation ◽  
Octave Band ◽  
Band Center ◽  
Heavy Weight ◽  
Concrete Building ◽  
Floor Structure ◽  
Insulation Performance

The air layer between the interior finishes and the structure is used as piping and wiring space. In many cases, ceilings and dry-type double floors are commonly constructed in Japan. However, the effect of the air layer of ceilings and dry-type double floors on the heavy-weight floor impact sound insulation performance has not yet quantitatively investigated. Therefore, in this study, the same floor and ceiling structures were constructed for concrete and CLT buildings, and the heavy-weight floor impact sound was investigated. As results, it was confirmed that the reduction amount of the heavy-weight floor impact sound by the ceiling tended to be smaller in CLT buildings than in concrete buildings. However, the trends were similar. Due to the dry-type double floor structure, the heavy-weight floor impact sound level was increased in concrete building and decreased in CLT building at 63 Hz in the octave band center frequency band. Therefore, it can be said that the dry-type double floor structure can be used to improve the heavy-weight floor impact sound performance in the CLT building.

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