Topological design of sandwich structures filling with poroelastic materials for sound insulation

A finite element model of the double-wall acoustic insulation structure with a air layer and an acoustic absorbent layer made of the poroelastic materials is set up, the responses of this acoustic-vibration system are calculated by using of the direct finite element method when having a diffuse incident acoustic field acting on the incident surface, the radiant acoustic power from the another surface are achieved, then the Transmission Loss(TL) are formulated using the incident acoustic power and the radiant acoustic power. The effects of the thicknesses, elastic modulus, flow resistivity and viscous lengths of the poroelastic materials on TL are analyzed. The results show that the thicknesses and elastic modulus have a significant effects on TL, TL are enhanced with the thicknesses increasing of the poroelastic materials layers, a 4.9dB addition of TL is achieved when thickness is added from 2cm to 3cm; TL are enhanced with the reduction of the elastic modulus in considered frequency range, and TL are reduced with the declining of viscous lengths and with the addition of the flow resistivity when the frequencies are higher than 600Hz.

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Sound insulation properties of sandwich structures on glass fiber felts

Fibers and Polymers ◽

10.1007/s12221-015-5200-6 ◽

2015 ◽

Vol 16 (7) ◽

pp. 1568-1577 ◽

Cited By ~ 15

Author(s):

Yong Yang ◽

Zhou Chen ◽

Zhaofeng Chen ◽

Renli Fu ◽

Yufang Li

Keyword(s):

Glass Fiber ◽

Sandwich Structures ◽

Sound Insulation

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Topological design of sandwich structures with graded cellular cores by multiscale optimization

Computer Methods in Applied Mechanics and Engineering ◽

10.1016/j.cma.2019.112749 ◽

2020 ◽

Vol 361 ◽

pp. 112749 ◽

Cited By ~ 17

Author(s):

Yan Zhang ◽

Mi Xiao ◽

Xiaoyu Zhang ◽

Liang Gao

Keyword(s):

Sandwich Structures ◽

Multiscale Optimization ◽

Topological Design

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Mechanical and Acoustic Performance of Sandwich Panels With Hybrid Cellular Cores

Journal of Vibration and Acoustics ◽

10.1115/1.4040514 ◽

2018 ◽

Vol 140 (6) ◽

Cited By ~ 7

Author(s):

Qing Li ◽

Deqing Yang

Keyword(s):

Mechanical Performance ◽

Transmission Loss ◽

Sandwich Structures ◽

Dynamic Performance ◽

Sandwich Panels ◽

Normal Incidence ◽

Spectral Element ◽

Sound Insulation ◽

Insulation Property ◽

Acoustic Performance

Sandwich structures that are embedded with cellular materials show excellent performance in terms of mechanics, electromagnetics, and acoustics. In this paper, sandwich panels with hybrid cellular cores of hexagonal, re-entrant hexagonal, and rectangular configurations along the panel surface are designed. The spectral element method (SEM) is applied to accurately predict the dynamic performance of the sandwich panels with a reduced number of elements and the system scale within a wide frequency range. The mechanical performance and the acoustic performance at normal incidence of the proposed structures are investigated and compared with conventional honeycomb panels with fixed cell geometries. It was found that the bending stiffness, fundamental frequencies, and sound transmission loss (STL) of the presented sandwich panels can be effectively changed by adjusting their hybrid cellular core configurations. Shape optimization designs of a hybrid cellular core for maximum STL are presented for specified tonal and frequency band cases at normal incidence. Hybrid sandwich panels increase the sound insulation property by 24.7%, 20.6%, and 109.6% for those cases, respectively, compared with conventional panels in this study. These results indicate the potential of sandwich structures with hybrid cellular cores in acoustic attenuation applications. Hybrid cellular cores can lead to inhomogeneous mechanical performance and constitute a broader platform for the optimum mechanical and acoustic design of sandwich structures.

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Vibration and Sound Transmission Performance of Sandwich Panels with Uniform and Gradient Auxetic Double Arrowhead Honeycomb Cores

Shock and Vibration ◽

10.1155/2019/6795271 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Qing Li ◽

Deqing Yang

Keyword(s):

Transmission Loss ◽

Sandwich Structures ◽

Sandwich Panels ◽

Sound Transmission ◽

Bending Stiffness ◽

Mode Shapes ◽

Sound Insulation ◽

Transmission Performance ◽

Constant Weight ◽

Honeycomb Sandwich

Auxetic mechanical metamaterials that exhibit a negative Poisson’s ratio (NPR) can be artificially designed to exhibit a unique range of physical and mechanical properties. Novel sandwich structures composed of uniform and gradient auxetic double arrowhead honeycomb (DAH) cores were investigated in terms of their vibration and sound transmission performance stimulated by nonhomogeneous metamaterials with nonperiodic cell geometries. The spectral element method (SEM) was employed to accurately evaluate the natural frequencies and dynamic responses with a limited number of elements at high frequencies. The results indicated that the vibrating mode shapes and deformations of the DAH sandwich models were strongly affected by the patterned gradient metamaterials. In addition, the sound insulation performance of the considered DAH sandwich models was investigated regarding the sound transmission loss (STL) from 1 Hz to 1500 Hz under a normal incident planar wave, and this performance was compared with that for hexagonal honeycomb sandwich panels. A programmable structural-acoustic optimization was implemented to maximize the STL while maintaining a constant weight and high strength. The results showed that the uniform DAH sandwich models with larger NPRs generally exhibited better vibration and acoustic attenuation behaviors and that the optimized gradient increasing NPR models yielded higher STL values than the optimized gradient decreasing NPR models for two specified frequency cases, with improvements of 6.52 dB and 2.52 dB and a higher bending stiffness but a lower overall STL. Thus, sandwich panels consisting of auxetic DAHs can achieve desirable vibroacoustic performance with a higher bending stiffness than conventional hexagonal honeycomb sandwich structures, and the design of gradient DAHs can be extended to obtain optimized vibration and noise-control capabilities.

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