Sound insulation performance of membrane-type metamaterials combined with pyramidal truss core sandwich structure

2020 ◽  
pp. 113257
Author(s):  
Yu-Zhou Wang ◽  
Li Ma
Keyword(s):  
Sandwich Structure ◽  
Sound Insulation ◽  
Truss Core ◽  
Pyramidal Truss ◽  
Membrane Type ◽  
Insulation Performance

Sound insulation performance of pyramidal truss core sandwich structure with frame

2021 ◽  
pp. 109963622110288
Author(s):  
Yu-Zhou Wang ◽  
Li Ma
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structure ◽  
Transmission Loss ◽  
Low Frequency ◽  
Sound Insulation ◽  
Geometrical Parameters ◽  
Acoustic Performance ◽  
Truss Core ◽  
Pyramidal Truss ◽  
Wave Angle

Recently, sandwich structures have been widely used in different fields because of their good mechanical properties, but these structures are weak in acoustic performance. In this paper, by combining pyramidal truss core sandwich structure with frame, a new structure is proposed with both good mechanical properties and excellent acoustic performance at low frequency. An analytical model of the pyramidal truss core sandwich structure with frame is developed to investigate the sound transmission loss (STL) performance. Finite element method (FEM) is also used to investigate the STL performance at low frequency. The effects of the incident wave angle and the geometrical parameters on the STL of the structure are discussed.

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.

Theoretical Study of Sound Insulation Simulations (About Attaching Effect of Sound Absorbing Material and Consideration of Sound Insulation Performance by Height of Origami Core)

2021 ◽  
Author(s):  
Aya Abe ◽  
Haruki Yashiro ◽  
Ichiro Hagiwara
Keyword(s):  
Aspect Ratio ◽  
Flat Plate ◽  
High Aspect Ratio ◽  
Theoretical Method ◽  
Sound Insulation ◽  
Truss Core ◽  
Multi Stage ◽  
Absorbing Material ◽  
Insulation Performance ◽  
Press Molding

Abstract We have developed a new truss core panel by origami forming to get the higher aspect ratio than that by multi-stage press molding. Our object is to apply the new origami truss core to the train floor. Whether or not this goal can be achieved depends on whether this new origami truss core with a high aspect ratio has excellent sound insulation characteristics. Therefore, as a development of the analysis technology by FEM which accurately estimates the sound insulation characteristics, at first, the relation between the aspect ratio and the sound insulation performance is discussed in the flat plate with one core. So far, sound insulation simulations using FEM did not match with theory of the mass law. However, this can be achieved by setting the end of the transmitted side to be a nonreflective boundary. In this paper, to generalize this method, it is determined theoretically that the sound pressures from the FEM can be separated accurately into the sound pressures of the forward and backward waves from Helmholtz’s equation. Then, the sound insulation characteristics of a flat plate obtained using the proposed theoretical method and the conventional method are compared while assuming that the flat plate is a rigid body. In addition, the validity of the proposed method is confirmed by evaluating the effect of attaching a sound absorbing material to the plate. Furthermore, application of the proposed method to a flat plate with a truss core and an examination of whether a high aspect ratio is advantageous for sound insulation are also presented.

scholarly journals Compressive and Shear Responses of Shaped-sheet Pyramidal Truss Core for Reinforced Sandwich Structure

2014 ◽  
Vol 81 ◽  
pp. 1121-1126
Author(s):  
Sung-Uk Lee ◽  
Dong-Hyo Lee ◽  
Eun-Ho Lee ◽  
Dong-Yol Yang
Keyword(s):  
Sandwich Structure ◽  
Truss Core ◽  
Pyramidal Truss

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.

Characteristics of Truss Core Created by Origami Forming Method

2019 ◽  
Author(s):  
Aya Abe ◽  
Kosuke Terada ◽  
Haruki Yashiro ◽  
Ichiro Hagiwara
Keyword(s):  
Sound Insulation ◽  
Honeycomb Core ◽  
Bending Tests ◽  
Three Point Bending ◽  
Mountain Valley ◽  
The Core ◽  
Truss Core ◽  
Drop Tests ◽  
Insulation Performance ◽  
Cushioning Material

Abstract The truss core surpasses the honeycomb core depending on the tasks. The height of core is limited by press forming and so on. Therefore, we developed a method by folding mountain / valley lines like origami. The origami forming method has the feature that it can be done from paper to metal by the same method. By examining three-point bending tests, drop tests, and analyzing them, we show that the structure that space-filled with cores obtained by the origami forming method called ATCP will be a box for both excellent cushioning material and transporting. Moreover, we also show that the core structure obtained by this has excellent sound insulation performance.

Sign in / Sign up

Export Citation Format

Share Document