Damping Structural Resonances Using Viscoelastic Shear-Damping Mechanisms: Part I—Design Configurations

1961 ◽  
Vol 83 (4) ◽  
pp. 403-413 ◽  
Author(s):  
Jerome E. Ruzicka
Keyword(s):  
Vibration Control ◽  
Dynamic Characteristics ◽  
Dynamic Environments ◽  
Resonant Vibration ◽  
Damping Properties ◽  
Structural Damping ◽  
Current Design ◽  
Flexural Vibrations ◽  
Shear Damping ◽  
General Dynamic

This paper considers the problem of resonant vibration control in designing structures to function in modern dynamic environments. Methods of specifying structural damping are given and damping properties of engineering materials are reviewed. The disadvantages of some current design practices are outlined and special structural designs which incorporate viscoelastic shear-damping mechanisms are suggested as a method of controlling the resonant flexural vibrations of structures. The general dynamic characteristics and design philosophy of structures and strip dampers (additive damping techniques) that incorporate viscoelastic shear-damping mechanisms are discussed. A description is given of some parameters useful in the design of viscoelastic-damped structures.

Damping Performance of Polychloroprene Rubber for Unconstrained Damping Applications

2021 ◽  
Vol 106 ◽  
pp. 131-136
Author(s):  
Prasanth Kumar Mallipudi ◽  
Padala Jyothi ◽  
N. Ramanaiah ◽  
V.V.S. Bhaskara Raju
Keyword(s):  
Vibration Control ◽  
Layer Thickness ◽  
Dynamic Characteristics ◽  
Loss Factor ◽  
Structural Response ◽  
Experimental Results ◽  
Viscoelastic Layer ◽  
Damping Properties ◽  
Structural Damping ◽  
Static And Dynamic Characteristics

Damping properties are crucial in determining the dynamic structural response. In this paper, the experimental results for Neoprene rubber of 40, 50 and 60 shore A hardness are reported in view of improving structural damping to control noise and vibrations. Additionally, the system loss factors of the unconstrained layer damped structures of same material were predicted by Ross-Kerwin-Ungar equation to validate the obtained experimental results. The results showed that Neoprene rubber (also known as Polychloroprene) of 60 shore A showed better static and dynamic characteristics than those of the 40 and 50 shore A hardness. The system loss factor results reached the saturation when the applied viscoelastic layer thickness was increased from 40 mm to 50 mm in unconstrained damping. As such, the proposed method can help to build a database of the properties of various materials which are applicable in the design of noise and vibration control.

The Effect of Structural Damping on the Forced Vibrations of Cylindrical Sandwich Shells

1966 ◽  
Vol 88 (3) ◽  
pp. 318-323 ◽  
Author(s):  
I. W. Jones ◽  
V. L. Salerno
Keyword(s):  
Approximate Formula ◽  
Forced Vibrations ◽  
Radial Vibration ◽  
Radial Load ◽  
Resonant Response ◽  
Damping Properties ◽  
Structural Damping ◽  
Resonant Vibrations ◽  
Cylindrical Sandwich Shell ◽  
Time Harmonic

This paper presents an examination of the effects of structural damping on the axisymmetric vibrations of a cylindrical sandwich shell. It is shown that the use of core materials with high damping properties can result in large reductions in resonant response over conventional materials. The radial vibration of the shell resulting from a time harmonic radial load is first calculated by an exact method. The radial vibration is then calculated by an approximate formula, which requires only a knowledge of the damping properties and the natural (undamped) modes. In numerical examples the resonant vibrations of two steel-faced cylinders are compared. One has a polymeric, the other an elastomeric core. The results indicate that for the assumed conditions they are both effective for suppressing resonant vibration, the polymeric core being generally more effective than the elastomeric core.

Dynamics of a Rotating Flexible Multi-Link With Viscoelastic Constraining Layers

1993 ◽  
Author(s):  
H. S. Tzou ◽  
G. C. Wan
Keyword(s):  
Vibration Control ◽  
High Precision ◽  
Structural Systems ◽  
Damping Properties ◽  
Passive Vibration Control ◽  
Viscoelastic Dampers ◽  
Viscoelastic Layers ◽  
Stiffness And Damping ◽  
Dynamics And Vibration

Abstract Due to an increased flexibility of modern mechanical and structural systems, effective vibration control becomes essential to their high-precision operations. In this paper, dynamics and vibration control of a rotating multi-link are studied. Passive vibration control of the link with distributed viscoelastic layers is studied. Effectiveness of the distributed viscoelastic dampers with various stiffness and damping properties is investigated.

Test of Thick Rubber Bearings on its Compressive Properties

2014 ◽  
Vol 919-921 ◽  
pp. 348-354 ◽  
Author(s):  
Hao Wen Chen ◽  
Peng Pan ◽  
Jun Cai Liu ◽  
Yu Sakurai ◽  
Masahiro Nakamura ◽  
...  
Keyword(s):  
Vibration Control ◽  
Steel Plates ◽  
Temperature Dependency ◽  
Test Results ◽  
Compressive Properties ◽  
Frequency Dependency ◽  
Current Design ◽  
High Damping Rubber ◽  
The Many ◽  
Rubber Bearings

Vibration is an important comfort issue for the metro surrounding buildings. Among the many methods of subway vibration control, building isolation is the necessary supplement to the track isolation for metro surrounding buildings with sensitive constructive forms or specific comfort needs. Laminated rubber bearings are widely used for the building isolation. In order to further improve the isolation effectiveness, researchers intend to use laminated rubber bearings with relatively thick rubber layers. However, the frequency dependency and temperature dependency are not well explored for the thick rubber bearings. And since constrains from the steel plates to rubber layers are relatively small for thick rubber bearings, its not clear if it is accurate to simply apply the equations for common laminated rubber bearings to the thick ones. In this paper, a compressive properties test is carried out for both thick and thin rubber bearings. Both thick and thin rubber bearings are manufactured by a kind of High Damping Rubber (HDR) and a kind of Nature Rubber (NR). The frequency dependency and temperature dependency are tested. The accuracy of applying the current design equations to thick rubber bearings is discussed based on the test results.

Vertical and Horizontal Seismic Response Analyses of Long-Span and Single-Layer Spherical Lattice Shell Structure

2014 ◽  
Vol 602-605 ◽  
pp. 602-605
Author(s):  
Jin Sheng He ◽  
She Liang Wang
Keyword(s):  
Vibration Control ◽  
Shell Structure ◽  
Response Spectrum ◽  
Single Layer ◽  
Internal Force ◽  
Seismic Load ◽  
Seismic Responses ◽  
Long Span ◽  
Current Design ◽  
Lattice Shell

The dynamic characteristics of 80 m single-layer spherical lattice shell structure are analyzed to control its vibration under seismic load. Through the response spectrum curve of current design specification, the analyses for the vertical and horizontal seismic responses of the single-layer spherical lattice shell structure are made by CQC, and the displacement response of the nodes and internal force of the rods unit are calculated respectively. The calculation results show that the vertical and horizontal seismic responses of the long-span lattice shell structure are in great difference, and should be performed in vibration control at the same time, which could provide certain references for the seismic design and vibration control of single-layer spherical lattice shell structure.

Vibration Control in Turbomachinery Blading Using Lacing Wires

1995 ◽  
Author(s):  
Robert X. Wang ◽  
Graham M. Chapman
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Dynamic Characteristics ◽  
Vibration Analysis ◽  
Finite Element Modelling ◽  
Speckle Pattern ◽  
Electronic Speckle Pattern Interferometry ◽  
Element Modelling ◽  
Wire Vibration ◽  
Theoretical Results

Abstract In turbomachinery practice the use of inter-blade coupling is an accepted procedure. The use of lacing wires in highly stressed short blading introduces damping and also modifies the vibration characteristics of the blading. This paper reports on a study into the dynamic characteristics of single blades with a lacing wire. Vibration analysis is carried out using finite element modelling. The theoretical results are verified using Electronic Speckle Pattern Interferometry technique (ESPI).

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