scholarly journals Analysis of Sound Insulation Mechanism and Optimization Design of an Acoustic Coating Layer with Multi-section Cylindrical Cavities

2021 ◽  
Vol 1102 (1) ◽  
pp. 012009
Author(s):  
J L Zhou ◽  
X J Meng ◽  
H D Huang Fu ◽  
J H Zhang ◽  
K Su ◽  
...  
2010 ◽  
Vol 163-167 ◽  
pp. 2410-2414
Author(s):  
Jian Xi Mao

In order to acquire a high quality of living environment, it is necessary to investigate the subjects of floor impact sound insulation. According to the characteristics of optimization design method and restricted optimization math model, the sound transmission between floor and adjacent room down through floating floor has been modeled in a finite-element method. Floating floor structure are studied to realize the design optimization when the room average sound pressures are selected as objective function. Predicted results show that when keep the whole thickness of floating floor fixed, result of dynamics optimization design can reduce room average sound pressure effectively. And when keep the whole thickness of floating floor unfixed, optimization results have been gotten on the total thickness of floor layer and resilient interlayer of the floating floor, and the average sound-pressure in room is lower than original one availably.


2015 ◽  
Vol 64 (15) ◽  
pp. 154301
Author(s):  
Huang Ling-Zhi ◽  
Xiao Yong ◽  
Wen Ji-Hong ◽  
Yang Hai-Bin ◽  
Wen Xi-Sen

2021 ◽  
Vol 149 (6) ◽  
pp. 4398-4409
Author(s):  
Javier Hernan Vazquez Torre ◽  
Jonas Brunskog ◽  
Vicente Cutanda Henriquez ◽  
Jaesoon Jung

2020 ◽  
Vol 64 (1-4) ◽  
pp. 165-172
Author(s):  
Dongge Deng ◽  
Mingzhi Zhu ◽  
Qiang Shu ◽  
Baoxu Wang ◽  
Fei Yang

It is necessary to develop a high homogeneous, low power consumption, high frequency and small-size shim coil for high precision and low-cost atomic spin gyroscope (ASG). To provide the shim coil, a multi-objective optimization design method is proposed. All structural parameters including the wire diameter are optimized. In addition to the homogeneity, the size of optimized coil, especially the axial position and winding number, is restricted to develop the small-size shim coil with low power consumption. The 0-1 linear programming is adopted in the optimal model to conveniently describe winding distributions. The branch and bound algorithm is used to solve this model. Theoretical optimization results show that the homogeneity of the optimized shim coil is several orders of magnitudes better than the same-size solenoid. A simulation experiment is also conducted. Experimental results show that optimization results are verified, and power consumption of the optimized coil is about half of the solenoid when providing the same uniform magnetic field. This indicates that the proposed optimal method is feasible to develop shim coil for ASG.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


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