Preparation of modified polyvinyl formal vibration‐damping material and its application in strawberry

2021 ◽  
Author(s):  
Yiqin Zhang ◽  
Honglei Mu ◽  
Haiyan Gao ◽  
Hangjun Chen ◽  
Weijie Wu ◽  
...  
Keyword(s):  
Vibration Damping ◽  
Polyvinyl Formal ◽  
Damping Material

The Application of BESO in Vibration Damping of Ship Plate

2013 ◽  
Vol 572 ◽  
pp. 185-188 ◽  
Author(s):  
Xiao Yan Teng ◽  
Jia Shan Han ◽  
Liang Peng
Keyword(s):  
Natural Vibration ◽  
Target Function ◽  
Vibration Damping ◽  
Natural Vibration Frequency ◽  
Constraint Condition ◽  
Evolutionary Structural Optimization ◽  
Damping Material ◽  
Reasonable Result ◽  
Beso Method ◽  
Original Amount

Based on the bi-directional evolutionary structural optimization (BESO), the method of determining the adhesion position of the damping material is proposed in this paper, which is applicable to the vibration damping of ship plate. In this method, the needed amount of damping material is taken as the constraint condition, and the maximization of one natural vibration frequency of the structure is taken as the target function. A thin plate structure with both ends constraints has been taken as an example to get the best topology structure of its adhesion damper by taking the BESO method. The result of optimization shows that it still meets the damping requirements when the needed amount of damping material decreases by about 50% of the original amount. The reasonable result demonstrates the effectiveness and engineering value of the method.

Topology Optimization of Carbon Nanotube Reinforced Damping Layers

Aerospace ◽  
2005 ◽  
Author(s):  
Arnold Lumsdaine ◽  
Mohan Damu
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Topology Optimization ◽  
Polymer Matrix ◽  
Vibration Damping ◽  
Constrained Layer Damping ◽  
Damping Properties ◽  
Reinforced Polymers ◽  
Damping Material ◽  
Layer Structures

Topology optimization has been successfully used for improving vibration damping in constrained layer damping structures with viscoelastic materials. Reinforcing carbon nanotubes in a polymer matrix greatly influences the mechanical properties of the polymer. Such nanotube-reinforced polymers (NRP) can be used to further enhance the damping properties of the constrained layer structures. The inclusion of nanotubes into a polymer matrix provides a new design variable in the topology optimization studies on such structures. In this work, the topology optimization of structures using such NRP as the damping material is performed. The resulting structures show a phenomenal improvement in damping. Moreover, a more efficient method is used for the optimization process.

Viscoelastic Vibration Damping Materials for Application in a Temperature Range above 150°C

2017 ◽  
Vol 730 ◽  
pp. 569-573 ◽  
Author(s):  
Wen Fei Wang ◽  
Xin Zhi Lin ◽  
Yu Liang Ma
Keyword(s):  
High Temperature ◽  
Bulk Material ◽  
Vibration Damping ◽  
Temperature Range ◽  
Polymer Resin ◽  
Young’S Moduli ◽  
Damping Material ◽  
Viscoelastic Damping Material ◽  
New Type ◽  
Damping Materials

We demonstrate a new type of viscoelastic vibration damping material with high damping performances (tan δ=E′/E′′ ≥0.3 where E′ and E′′ are the storage and loss Young’s moduli, respectively) at a high temperature range between 200°C and 250°C utilizing a special polymer resin of higher glass transition temperature corresponding to the application temperature range and larger pendant groups offering higher efficiency of the energy dissipation. In addition, the damping property of the bulk material reinforced with glass fiber will be significantly improved, where the peak tan δ value can reach 0.7. In this paper, we put the emphasis on the preparation process and properties characterization of this new type material, and try to provide a new method to fabricate a viscoelastic damping material (VDM) usable for applications in the field of high temperature vibration reduction, in contrast to the conventional ones whose damping properties will dramatically decay once the ambient temperature is above 100°C.

Experimental Study of Vibration Damping in a Modified Elastic Wedge of Power-Law Profile

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
J. Javier Bayod
Keyword(s):  
Power Law ◽  
High Frequency ◽  
Vibration Damping ◽  
Constant Thickness ◽  
Practical Implementation ◽  
High Frequency Range ◽  
Elastic Wedge ◽  
Frequency Range ◽  
Passive Damping ◽  
Damping Material

The objective of this research is to evaluate and propose a modified elastic wedge as passive damping system for structural damping. An elastic wedge is a plate whose thickness decreases smoothly toward zero. It has been proposed as an effective passive damping system to reduce structural vibration, especially in the high frequency range. Several authors have researched elastic wedge theory and showed that if the thickness of a plate decreases toward zero following a power law function, the flexural waves traveling in that plate do not suffer reflection along their path. That energy accumulates at the zero thickness edge, which results in a very efficient damping. In practice, manufacturing a zero thickness edge is not possible and a large amount of the wave energy is reflected at the thinner edge. However, when a small quantity of damping material is added on that edge, a very effective damping can be achieved. The damping effectiveness of the elastic wedge increases proportionally to the thinness of the edge for a given quantity of the added damping material. However, manufacturing of an elastic wedge with a very thin edge is economically costly since high precision machining is required. This presents a problem for practical implementation into the manufacturing line. In this paper, a modified elastic wedge is proposed to facilitate manufacturing and to reduce cost so that practical implementation is possible. In the proposed modified elastic wedge, the thin edge has a thickness achievable with conventional tools. Then, to increase its damping effectiveness, the thin edge is extended for some length with constant thickness. Finally, damping material is added on the extended part. Experimental and finite element method (FEM) frequency response analyses were carried out with a modified elastic wedge. The results show that the proposed modified elastic wedge can also achieve very effective vibration damping, especially in the high frequency range, while being manufactured with conventional tools. This method is currently under evaluation for noise reduction in structures of large dimensions, like platelike components of ship structures, or other machinery to reduce vibration and noise emission, and where cost and manufacturing accuracy limit the application of the conventional elastic wedge.

Properties of Sponge Rubber as a Material for Damping Vibration and Shock

1939 ◽  
Vol 12 (1) ◽  
pp. 105-111 ◽  
Author(s):  
C. W. Kosten ◽  
C. Zwikker
Keyword(s):  
Mechanical Impedance ◽  
Vibration Damping ◽  
Damping Properties ◽  
Air Content ◽  
Damping Material ◽  
The Way

Abstract In order to obtain vibration-proof mountings, use is frequently made of sponge rubber. In this paper investigations are described concerning the factors on which its vibration damping properties depend. Formulas have been deduced for the mechanical impedance of sponge rubber, taking into account the presence of pores in the material. The formulas render the results of the measurements satisfactorily and, at the same time, they show how the qualities depend on factors such as porosity, kind of rubber, size of the pores, dimensions, etc. Under Section 6 we have examined more closely the choice of sponge rubber and the way of utilizing it in order to obtain the best results. 1. General.—Sponge rubber appears to possess excellent qualities as a damping material. This being so, the question arises as to what part is played by the air it contains, and how this air content must be fixed to obtain the best results. We have attempted to answer this question by paying attention to the mechanical impedance of sponge rubber.

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