scholarly journals Multi-Objective Optimization of Acoustical Properties of PU-Bamboo-Chips Foam Composites

2017 ◽  
Vol 42 (4) ◽  
pp. 707-714 ◽  
Author(s):  
Yang Jiang ◽  
Shuming Chen ◽  
Dengfeng Wang ◽  
Jing Chen
Keyword(s):  
Orthogonal Array ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Silicone Oil ◽  
Taguchi Methods ◽  
Optimization Approach ◽  
Multi Objective Optimization ◽  
Signal To Noise ◽  
Acoustical Properties ◽  
Pu Foams

Abstract In this study, an effective optimization approach was proposed to improve acoustical behaviors of PU foams. The important parameters of PU foams: content of water, silicone oil and catalyst A1 were chosen and their effects on sound absorption coefficient and transmission loss of PU foams were studied by using Taguchi methods. In addition, bamboo chips were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Four controlled factors: the content of water, silicone oil, catalyst A1 and bamboo chips with three levels for each factor were chosen and Taguchi method based on orthogonal array L9(34) was employed to conduct the experiments. Based on the results of Taguchi’s orthogonal array L9(34), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU-bamboo-chips foam composites.

scholarly journals The Effects of Various Additive Components on the Sound Absorption Performances of Polyurethane Foams

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Shuming Chen ◽  
Yang Jiang ◽  
Jing Chen ◽  
Dengfeng Wang
Keyword(s):  
Absorption Coefficient ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Polyurethane Foams ◽  
Acoustic Properties ◽  
Acoustic Absorption ◽  
Absorption Properties ◽  
Maximum Enhancement ◽  
Flexible Polyurethane ◽  
Pu Foams

Flexible polyurethane (PU) foams comprising various additive components were synthesized to improve their acoustic performances. The purpose of this study was to investigate the effects of various additive components of the PU foams on the resultant sound absorption, which was characterized by the impedance tube technique to obtain the incident sound absorption coefficient and transmission loss. The maximum enhancement in the acoustic properties of the foams was obtained by adding fluorine-dichloroethane (141b) and triethanolamine. The results showed that the acoustic absorption properties of the PU foams were improved by adding 141b and triethanolamine and depended on the amount of the water, 141b, and triethanolamine.

scholarly journals An analysis of implementation of Taguchi method to improve production of pulp on hydrapulper milling

2019 ◽  
Vol 7 (2) ◽  
pp. 125
Author(s):  
Hernadewita Hernadewita ◽  
I Rochmad ◽  
Hendra Hendra ◽  
Hermiyetti Hermiyetti ◽  
E.N.S. Yuliani
Keyword(s):  
Taguchi Method ◽  
Orthogonal Array ◽  
Milling Time ◽  
Quality Parameter ◽  
Milling Process ◽  
Taguchi Methods ◽  
Signal To Noise ◽  
Taguchi Doe ◽  
Pulp Consistency ◽  
Level 2

<div><p class="TtuloAbstract">Abstract: Taguchi method is one of a design of experimental (DOE), by  using statistical approach to optimize the process parameters and maintaining the minimum variability and also improve the quality of product.  Based on data characterisation, Nominal is Best in Taguchi methods is suitable application in this study. Its describe the procedures and steps that occur in DOE to find an optimum quality parameter corresponding quality characterisation. Nominal is the best applied in milling process of pulp on the hydrapulper with pulp freeness 650 Canadian Standard Freeness (CSF). The result is shown by orthogonal array, Signal-to-Noise (S/N) Ratio and analysis of variances (ANOVA). Three factors cosidered in this study and namely the composition of pulp (waste paper), pulp consistency and milling time. The experiment will conducted after determination of each level and  the appropriate orthogonal array was selected. After measuring of pulp freeness produced by the pulp milling on the hydrapulper, then Signal-to-Noise (S/N) Ratio is calculated. As the conclussion, the factors and levels of optimum freeness obtained, pulp composition in level 1 (100%), pulp consistency at level 2 (8%) and milling time factor in level 2 (45 minutes). The result of experimental verification was interpreted in the conclusion.</p></div><p class="Abstract"><strong>Keywords:</strong> Taguchi; DOE; pulp; hydrapulper; Nominal is the Best; ANOVA</p>

Study on Sound Absorption and Transmission Loss of Transversely Isotropic Multi Layers Porous Material

2010 ◽  
Author(s):  
Reza Keshavarz ◽  
Abdolreza Ohadi
Keyword(s):  
Absorption Coefficient ◽  
Transfer Matrix ◽  
Sound Absorption ◽  
Transmission Loss ◽  
Transversely Isotropic ◽  
Angle Of Incidence ◽  
Isotropic Layer ◽  
Acoustical Properties ◽  
Porous Layers ◽  
Total Displacement

In this work, acoustic wave propagation at oblique incidence in a multi layers material that consists of different layers such as air, homogenous and transversely isotropic porous layers is described. Transfer matrix method (TMM) is applied to compute acoustical properties of multilayer system. For transversely isotropic layer, the transfer matrix based on total displacement formulation of the Biot’s theory is used. Finally, for multi layers porous materials, variation of the sound absorption coefficient and transmission loss versus frequency and angle of incidence are determined. Analysis shows that transversely isotropic porous layers changes the absorption coefficient and improve the transmission loss.

scholarly journals Multi-Objective Multidisciplinary Design Optimization of a Robotic Fish System

2021 ◽  
Vol 9 (5) ◽  
pp. 478
Author(s):  
Hao Chen ◽  
Weikun Li ◽  
Weicheng Cui ◽  
Ping Yang ◽  
Linke Chen
Keyword(s):  
Design Optimization ◽  
Optimization Algorithm ◽  
Multidisciplinary Design Optimization ◽  
Robotic Fish ◽  
Multidisciplinary Design ◽  
Optimization Approach ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Cfd Method ◽  
The Individual

Biomimetic robotic fish systems have attracted huge attention due to the advantages of flexibility and adaptability. They are typically complex systems that involve many disciplines. The design of robotic fish is a multi-objective multidisciplinary design optimization problem. However, the research on the design optimization of robotic fish is rare. In this paper, by combining an efficient multidisciplinary design optimization approach and a novel multi-objective optimization algorithm, a multi-objective multidisciplinary design optimization (MMDO) strategy named IDF-DMOEOA is proposed for the conceptual design of a three-joint robotic fish system. In the proposed IDF-DMOEOA strategy, the individual discipline feasible (IDF) approach is adopted. A novel multi-objective optimization algorithm, disruption-based multi-objective equilibrium optimization algorithm (DMOEOA), is utilized as the optimizer. The proposed MMDO strategy is first applied to the design optimization of the robotic fish system, and the robotic fish system is decomposed into four disciplines: hydrodynamics, propulsion, weight and equilibrium, and energy. The computational fluid dynamics (CFD) method is employed to predict the robotic fish’s hydrodynamics characteristics, and the backpropagation neural network is adopted as the surrogate model to reduce the CFD method’s computational expense. The optimization results indicate that the optimized robotic fish shows better performance than the initial design, proving the proposed IDF-DMOEOA strategy’s effectiveness.

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