scholarly journals On-demand optimize design of sound-absorbing porous material based on multi-population genetic algorithm

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 122-132
Author(s):  
Yonghua Wang ◽  
Shengfu Liu ◽  
Haiquan Wu ◽  
Chengchun Zhang ◽  
Jinkai Xu ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Porous Material ◽  
High Frequency ◽  
Population Genetic ◽  
Sound Absorption ◽  
Perforated Plate ◽  
Noise Spectrum ◽  
Absorption Effect ◽  
Absorption Performance ◽  
Population Genetic Algorithm

AbstractPorous material (PM) shows good sound absorption performance, however, the sound absorbing property of PM with different parameters are greatly different. In order to match the most suitable absorbing materials with the most satisfactory sound-absorbing performance according to the noise spectrum in different practical applications, multi-population genetic algorithm is used in this paper to optimize the parameters of porous sound absorbing structures that are commonly used according to the actual demand of noise reduction and experimental verification. The results shows that the optimization results of multi-population genetic algorithm are obviously better than the standard genetic algorithm in terms of sound absorption performance and sound absorption bandwidth. The average acoustic absorption coefficient of PM can reach above 0.6 in the range of medium frequency, and over 0.8 in the range of high frequency through optimization design. At a mid-to-high frequency environment, the PM has a better sound absorption effect and a wider frequency band than that of micro-perforated plate. However, it has a poor sound absorption effect at low frequency. So it is necessary to select suitable sound absorption material according to the actual noise spectrum.

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.

Sound absorption of a finite flexible micro-perforated panel absorber back by a rigid air cavity filled with a fibrous porous material

2021 ◽  
Vol 263 (3) ◽  
pp. 3625-3632
Author(s):  
Ho Yong Kim ◽  
Yeon June Kang
Keyword(s):  
Energy Dissipation ◽  
Porous Material ◽  
Fibrous Material ◽  
Alternative Energy ◽  
Sound Absorption ◽  
Sound Pressure ◽  
Absorption Coefficients ◽  
Air Cavity ◽  
Acoustic Cavity ◽  
Absorption Performance

Back by a rigid cavity filled with a layer of porous layer, the sound absorption performance of a micro-perforated panel (MPP) can be enhanced in comparison with other resonance based sound absorbers. In this paper, a theoretical model of a finite flexible MPP back by a rigid air cavity filled with a fibrous porous material is developed to predict normal sound absorption coefficients. Displacements of MPP and sound pressure field in fibrous porous material and acoustic cavity are expressed using a series of modal functions, and the sound absorption coefficients of MPP system are obtained. Additionally, comparison of energy dissipation by MPP and fibrous material is performed to identify effects of a fibrous material on the sound absorption of a MPP. As expected, at anti-resonance frequency of an MPP, the fibrous material provide an alternative energy dissipation mechanism.

scholarly journals Study on MPGA-BP of Gravity Dam Deformation Prediction

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaoyu Wang ◽  
Kan Yang ◽  
Changsong Shen
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Bp Neural Network ◽  
Population Genetic ◽  
Prediction Accuracy ◽  
Gravity Dam ◽  
Hydraulic Structures ◽  
Deformation Prediction ◽  
Multiple Population ◽  
Population Genetic Algorithm

Displacement is an important physical quantity of hydraulic structures deformation monitoring, and its prediction accuracy is the premise of ensuring the safe operation. Most existing metaheuristic methods have three problems: (1) falling into local minimum easily, (2) slowing convergence, and (3) the initial value’s sensitivity. Resolving these three problems and improving the prediction accuracy necessitate the application of genetic algorithm-based backpropagation (GA-BP) neural network and multiple population genetic algorithm (MPGA). A hybrid multiple population genetic algorithm backpropagation (MPGA-BP) neural network algorithm is put forward to optimize deformation prediction from periodic monitoring surveys of hydraulic structures. This hybrid model is employed for analyzing the displacement of a gravity dam in China. The results show the proposed model is superior to an ordinary BP neural network and statistical regression model in the aspect of global search, convergence speed, and prediction accuracy.

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