scholarly journals Parameter Optimization for Composite Structures of Microperforated Panel and Porous Metal for Optimal Sound Absorption Performance

2019 ◽  
Vol 9 (22) ◽  
pp. 4798 ◽  
Author(s):  
Haiqin Duan ◽  
Xinmin Shen ◽  
Fei Yang ◽  
Panfeng Bai ◽  
Xiaofang Lou ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Parameter Optimization ◽  
Composite Structure ◽  
Composite Structures ◽  
Sound Absorption ◽  
Structural Parameters ◽  
Porous Metal ◽  
Total Thickness ◽  
Frequency Range ◽  
Absorption Performance

The composite structure of a microperforated panel and porous metal is a promising sound absorber for industrial noise reduction, sound absorption performance of which can be improved through parameter optimization. A theoretical model is constructed for the composite structure of a microperforated panel and porous metal based on Maa’s theory and the Johnson–Champoux–Allard model. When the limited total thickness is 30 mm, 50 mm, and 100 mm respectively, dimensional optimization of structural parameters of the proposed composite structure is conducted for the optimal average sound absorption coefficient in the frequency range (2000 Hz, 6000 Hz) through a cuckoo search algorithm. Simulation models of the composite structures with optimal structural parameters are constructed based on the finite element method. Validations of the optimal composite structures are conducted based on the standing wave tube method. Comparative analysis of the theoretical data, simulation data, and experimental data validates feasibility and effectiveness of the parameter optimization. The optimal sandwich structure with an actual total thickness of 36.8 mm can obtain the average sound absorption coefficient of 97.65% in the frequency range (2000 Hz, 6000 Hz), which is favorable to promote practical application of the composite structures in the fields of sound absorption and noise reduction.

scholarly journals Preparation and Characterization of Gradient Compressed Porous Metal for High-Efficiency and Thin-Thickness Acoustic Absorber

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1413 ◽  
Author(s):  
Xiaocui Yang ◽  
Xinmin Shen ◽  
Panfeng Bai ◽  
Xiaohui He ◽  
Xiaonan Zhang ◽  
...  
Keyword(s):  
Sound Absorption ◽  
High Efficiency ◽  
Structural Parameters ◽  
Porous Metal ◽  
Theoretical Models ◽  
Absorption Efficiency ◽  
Total Thickness ◽  
Porous Metals ◽  
Absorption Coefficients ◽  
Optimal Average

Increasing absorption efficiency and decreasing total thickness of the acoustic absorber is favorable to promote its practical application. Four compressed porous metals with compression ratios of 0%, 30%, 60%, and 90% were prepared to assemble the four-layer gradient compressed porous metals, which aimed to develop the acoustic absorber with high-efficiency and thin thickness. Through deriving structural parameters of thickness, porosity, and static flow resistivity for the compressed porous metals, theoretical models of sound absorption coefficients of the gradient compressed porous metals were constructed through transfer matrix method according to the Johnson–Champoux–Allard model. Sound absorption coefficients of four-layer gradient compressed porous metals with the different permutations were theoretically analyzed and experimentally measured, and the optimal average sound absorption coefficient of 60.33% in 100–6000 Hz was obtained with the total thickness of 11 mm. Sound absorption coefficients of the optimal gradient compressed porous metal were further compared with those of the simple superposed compressed porous metal, which proved that the former could obtain higher absorption efficiency with thinner thickness and fewer materials. These phenomena were explored by morphology characterizations. The developed high-efficiency and thin-thickness acoustic absorber of gradient compressed porous metal can be applied in acoustic environmental detection and industrial noise reduction.

scholarly journals Identification of Acoustic Characteristic Parameters and Improvement of Sound Absorption Performance for Porous Metal

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 340 ◽  
Author(s):  
Xiaocui Yang ◽  
Xinmin Shen ◽  
Haiqin Duan ◽  
Xiaonan Zhang ◽  
Qin Yin
Keyword(s):  
Experimental Data ◽  
Composite Structures ◽  
Sound Absorption ◽  
Porous Metal ◽  
Cuckoo Search ◽  
Acoustic Characteristic ◽  
Identification Algorithm ◽  
Characteristic Parameters ◽  
Absorption Performance ◽  
Standing Wave Tube

Porous metal is widely used in the fields of sound absorption and noise reduction, and it is a critical procedure to identify acoustic characteristic parameters and to improve sound absorption performances. Based on the constructed theoretical sound absorption model and experimental data, acoustic characteristic parameters of the porous metal were identified through the cuckoo search identification algorithm, and their reliabilities were certified through comparing with these labeled parameters and further experimental validation. By adding the microperforated metal panel in front of the porous metal, a composite sound-absorbing structure was formed, which aimed to improve the sound absorption performance of the original porous metal by optimizing the parameters. Finite element simulation and a standing wave tube measurement were conducted to validate the effectiveness and practicability of the optimal composite sound-absorbing structure. Consistencies among theoretical predictions, simulation results, and experimental data proved the effectiveness of the identification and optimization method. When the target frequency ranges were 100–1000 Hz, 100–2000 Hz, 100–3000 Hz, and 100–4000 Hz. Actual average sound absorption coefficients of the optimal composite structures were 0.5154, 0.6369, 0.6770, and 0.7378, respectively, which exhibited the obvious improvements with a tiny increase in the occupied space and a small addition in weight.

scholarly journals Influences of Compression Ratios on Sound Absorption Performance of Porous Nickel–Iron Alloy

Metals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 539 ◽  
Author(s):  
Panfeng Bai ◽  
Xinmin Shen ◽  
Xiaonan Zhang ◽  
Xiaocui Yang ◽  
Qin Yin ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Compression Ratio ◽  
Sound Absorption ◽  
Iron Alloy ◽  
Porous Metal ◽  
Sound Absorption Coefficient ◽  
Porous Nickel ◽  
Nickel Iron ◽  
Absorption Performance ◽  
Nickel Iron Alloy

The improvement of sound absorption performance of porous metal is a focus of research in the field of noise reduction. Influences of compression ratios on sound absorption performance of a porous nickel–iron (Ni–Fe) alloy were investigated. The samples were compressed with ratios from 10% to 80% at an interval of 10%. Based on the standing wave method, sound absorption coefficients of compressed samples with different thicknesses were obtained. It could be found that with the same compression ratio, sound absorption performance was improved with the increase of thickness. Based on the modified Johnson–Allard model with a correction factor, the sound absorption coefficient of the porous Ni–Fe with a thickness of 20 mm for different compression ratios was derived, whose aim was to quantificationally analyze influences of the compression ratio. The results indicated that the sample with a compression ratio of 70% exhibited optimal sound absorption performance, and its average sound absorption coefficient reached 88.97% in a frequency range of 1000–6000 Hz. Meanwhile, the section morphologies of compressed samples were investigated by a scanning electron microscope, which studied the sound absorption performance by analyzing structures of the porous Ni–Fe samples with different compression ratios. The obtained achievements will promote the application of the porous Ni–Fe alloy in the field of acoustics.

The Influence of Structural Parameters on the Sound Absorption Performance of Micro Perforated Absorber

2014 ◽  
Vol 701-702 ◽  
pp. 424-427
Author(s):  
Meng Zi Sun ◽  
Fei Huang ◽  
Hua Jing Li
Keyword(s):  
Numerical Simulation ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Structural Parameters ◽  
Experimental Result ◽  
Laser Machining ◽  
Parameter Combination ◽  
Absorption Performance ◽  
High Absorption Coefficient ◽  
High Absorption

The sound absorption performance of MPA (micro perforated absorber) mainly depends on its structural parameters. Reasonable parameter combination will get a high absorption coefficient. In this paper numerical simulation was used to study sound absorption performance. By this means, the influence of the different parameters on the sound absorption performance are discovered. To verify the result of numerical simulation, MPA samples are fabricated using optimized parameters by laser machining method. The sound absorption performances of these samples are tested and the experimental result is consistent with that of numerical simulation.

Sound absorption of a thick micro-perforated panel with tapered sections

2021 ◽  
Vol 69 (4) ◽  
pp. 331-340
Author(s):  
Liyan He ◽  
Chenxi Li ◽  
Ying Hu ◽  
Haitao Wang ◽  
Qing Ran ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
High Frequency ◽  
Sound Absorption ◽  
Structural Parameters ◽  
Sound Absorption Coefficient ◽  
Frequency Range ◽  
Element Analysis ◽  
Fea Model ◽  
Fea Simulation ◽  
Engineering Projects

This article aims to investigate the sound absorbing properties of a thick microperforated panel (MPP) with tapered sections with finite element analysis (FEA) models. The FEA model was validated by using the measured sound absorption coefficients of a classic MPP sample and a proposed MPP sample. The FEA simulation and the experiments indicate that the tapered section can enhance the sound absorption coefficient. Moreover, the FEA model shows that the structural parameters of the tapered section can be optimized. The resonance frequency of the sound absorption coefficient moves to the high-frequency range, and the maximum sound absorption coefficient increases in three conditions, the tapered section moving toward the backing cavity, and the increase of the thickness and the bottom radius of the tapered section. Although the optimized configurations of the tapered section may vary with the structure parameters of the MPP, the tapered section can improve the sound absorbing properties of the classic MPP and could be promising in the noise and vibration engineering projects.

scholarly journals Acoustic Panels Made of Paper Sludge and Clay Composites

2021 ◽  
Vol 13 (2) ◽  
pp. 637
Author(s):  
Tomas Astrauskas ◽  
Tomas Januševičius ◽  
Raimondas Grubliauskas
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Composite Panel ◽  
Sound Absorption Coefficient ◽  
Core Material ◽  
Paper Sludge ◽  
Frequency Range ◽  
Absorption Properties ◽  
Air Gaps ◽  
The Core

Studies on recycled materials emerged during recent years. This paper investigates samples’ sound absorption properties for panels fabricated of a mixture of paper sludge (PS) and clay mixture. PS was the core material. The sound absorption was measured. We also consider the influence of an air gap between panels and rigid backing. Different air gaps (50, 100, 150, 200 mm) simulate existing acoustic panel systems. Finally, the PS and clay composite panel sound absorption coefficients are compared to those for a typical commercial absorptive ceiling panel. The average sound absorption coefficient of PS-clay composite panels (αavg. in the frequency range from 250 to 1600 Hz) was up to 0.55. The resulting average sound absorption coefficient of panels made of recycled (but unfinished) materials is even somewhat higher than for the finished commercial (finished) acoustic panel (αavg. = 0.51).

scholarly journals Diffuse Sound Absorptive Properties of Parallel-Arranged Perforated Plates with Extended Tubes and Porous Materials

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1091 ◽  
Author(s):  
Dengke Li ◽  
Daoqing Chang ◽  
Bilong Liu
Keyword(s):  
Boundary Condition ◽  
Porous Material ◽  
Porous Materials ◽  
Sound Absorption ◽  
Azimuthal Angle ◽  
Octave Band ◽  
Frequency Range ◽  
Absorption Coefficients ◽  
Perforated Plates ◽  
Absorption Performance

The diffuse sound absorption was investigated theoretically and experimentally for a periodically arranged sound absorber composed of perforated plates with extended tubes (PPETs) and porous materials. The calculation formulae related to the boundary condition are derived for the periodic absorbers, and then the equations are solved numerically. The influences of the incidence and azimuthal angle, and the period of absorber arrangement are investigated on the sound absorption. The sound-absorption coefficients are tested in a standard reverberation room for a periodic absorber composed of units of three parallel-arranged PPETs and porous material. The measured 1/3-octave band sound-absorption coefficients agree well with the theoretical prediction. Both theoretical and measured results suggest that the periodic PPET absorbers have good sound-absorption performance in the low- to mid-frequency range in diffuse field.

scholarly journals Non-Wovens as Sound Reducers

2018 ◽  
Vol 55 (2) ◽  
pp. 64-76
Author(s):  
D. Belakova ◽  
A. Seile ◽  
S. Kukle ◽  
T. Plamus
Keyword(s):  
Absorption Coefficient ◽  
Surface Density ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Insulation ◽  
Material Structure ◽  
Sound Transmission Loss ◽  
Sound Waves ◽  
Frequency Range

Abstract Within the present study, the effect of hemp (40 wt%) and polyactide (60 wt%), non-woven surface density, thickness and number of fibre web layers on the sound absorption coefficient and the sound transmission loss in the frequency range from 50 to 5000 Hz is analysed. The sound insulation properties of the experimental samples have been determined, compared to the ones in practical use, and the possible use of material has been defined. Non-woven materials are ideally suited for use in acoustic insulation products because the arrangement of fibres produces a porous material structure, which leads to a greater interaction between sound waves and fibre structure. Of all the tested samples (A, B and D), the non-woven variant B exceeded the surface density of sample A by 1.22 times and 1.15 times that of sample D. By placing non-wovens one above the other in 2 layers, it is possible to increase the absorption coefficient of the material, which depending on the frequency corresponds to C, D, and E sound absorption classes. Sample A demonstrates the best sound absorption of all the three samples in the frequency range from 250 to 2000 Hz. In the test frequency range from 50 to 5000 Hz, the sound transmission loss varies from 0.76 (Sample D at 63 Hz) to 3.90 (Sample B at 5000 Hz).

Utilization of Styrofoam ss Soundproofing Material with Auditory Frequency Range

2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Sjahrul Meizar Nasri ◽  
Iting Shofwati
Keyword(s):  
Hearing Loss ◽  
Absorption Coefficient ◽  
Sound Absorption ◽  
Noise Exposure ◽  
Preventive Action ◽  
Frequency Range ◽  
Acoustical Property ◽  
Noise Barrier ◽  
Polystyrene Waste ◽  
Action Methods

One of preventive action methods of hearing loss that number tend to increase is by using brick that made from Styrofoam which is expected to have the ability as a soundproof that can be used to control the noise. The aim of this research is to assess the use of sound absorption material in which utilizing Styrofoam to reduce the noise exposure. In this study, cement and find aggregate that contain the Styrofoam and sand are mixed with the composition 1:4 and 1:6 and also by adding the polystyrene waste as much as 0%, 20%, 40%, 60%, and 80%.  To determine the acoustical property of the mixture, the sound absorbing coefficient (α) was determined by using Four Microphones Impedance Tube (ISO 140-3). The results showed that the highest absorption coefficient value was at frequency 800 Hz by adding 80% Styrofoam for the composition of 1:4 at 0.4100 dB and at the frequency 800 Hz by adding 40% Styrofoam for the composition 1:6 at 0.5870 dB. Based on the results of this research, further study to potentially use Styrofoam as noise barrier is suggested.

scholarly journals Optimization and Validation of Sound Absorption Performance of 10-Layer Gradient Compressed Porous Metal

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 588 ◽  
Author(s):  
Fei Yang ◽  
Xinmin Shen ◽  
Panfeng Bai ◽  
Xiaonan Zhang ◽  
Zhizhong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Sound Absorption ◽  
Search Algorithm ◽  
Theoretical Data ◽  
Porous Metal ◽  
Cuckoo Search ◽  
Absorption Coefficients ◽  
Element Simulation ◽  
Absorption Performance

Sound absorption performance of a porous metal can be improved by compression and optimal permutation, which is favorable to promote its application in noise reduction. The 10-layer gradient compressed porous metal was proposed to obtain optimal sound absorption performance. A theoretical model of the sound absorption coefficient of the multilayer gradient compressed porous metal was constructed according to the Johnson-Champoux-Allard model. Optimal parameters for the best sound absorption performance of the 10-layer gradient compressed porous metal were achieved by a cuckoo search algorithm with the varied constraint conditions. Preliminary verification of the optimal sound absorber was conducted by the finite element simulation, and further experimental validation was obtained through the standing wave tube measurement. Consistencies among the theoretical data, the simulation data, and the experimental data proved accuracies of the theoretical sound absorption model, the cuckoo search optimization algorithm, and the finite element simulation method. For the investigated frequency ranges of 100–1000 Hz, 100–2000 Hz, 100–4000 Hz, and 100–6000 Hz, actual average sound absorption coefficients of optimal 10-layer gradient compressed porous metal were 0.3325, 0.5412, 0.7461, and 0.7617, respectively, which exhibited the larger sound absorption coefficients relative to those of the original porous metals and uniform 10-layer compressed porous metal with the same thickness of 20 mm.

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