Performance of a Non Linear Dynamic Vibration Absorbers

2014 ◽  
Vol 31 (3) ◽  
pp. 345-353 ◽  
Author(s):  
F. Djemal ◽  
F. Chaari ◽  
J.-L. Dion ◽  
F. Renaud ◽  
I. Tawfiq ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Wide Band ◽  
Experimental Investigations ◽  
Vibration Absorbers ◽  
Dynamic Phenomenon ◽  
Jump Phenomenon ◽  
Cubic Nonlinearity ◽  
Linear Dynamic ◽  
Dynamic Vibration Absorbers ◽  
Linear And Nonlinear

AbstractThe most common method of vibration control is the use of the dynamic absorbers. Two types of absorbers can be found: Linear and nonlinear. The use of linear absorbers allows reducing vibration but only at the resonance frequency, whereas nonlinear absorbers attenuate vibration on a wide band of frequency. In this paper, a nonlinear two degrees of freedom (DOF) model is developed. A cubic nonlinearity induced by a gap is considered. The objective of the paper is to characterize nonlinear vibration of the system by applying explicit formulation (EF). An experimental study is performed to validate the numerical results. The jump phenomenon is the principal nonlinear dynamic phenomenon observed on both numerical and experimental investigations.

scholarly journals On-Line Modal Parameter Identification Applied to Linear and Nonlinear Vibration Absorbers

Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 119
Author(s):  
Luis Gerardo Trujillo-Franco ◽  
Gerardo Silva-Navarro ◽  
Francisco Beltran-Carbajal ◽  
Eduardo Campos-Mercado ◽  
Hugo Francisco Abundis-Fong
Keyword(s):  
Nonlinear Dynamic ◽  
Degrees Of Freedom ◽  
Flexible Structure ◽  
Primary System ◽  
Vibration Absorbers ◽  
Modal Parameter ◽  
Vibration Absorption ◽  
Dynamic Vibration ◽  
On Line ◽  
Linear And Nonlinear

A solution of the vibration attention problem on a flexible structure from a dynamic vibration absorption perspective is experimentally and numerically studied in this article. Linear and nonlinear dynamic vibration absorbers are properly implemented on a primary structure of n degrees of freedom through a modal decomposition analysis and using the tuning condition when the primary system has one single degree of freedom. A time-domain algebraic identification scheme for on-line modal parameter estimation of flexible structures is presented. A fast frequency estimation of harmonic excitation force is also obtained. A Hilbert transform analysis of the frequency response function for the case of nonlinear dynamic vibration absorption is introduced. In this way, influence of this particular passive nonlinear control device on system dynamic response can be determined. The proposed approach is validated on an harmonically perturbed building-like structure, which is discretized in a finite number of degrees of freedom. The flexible structure is subjected to resonant operational conditions, and coupled to a pendulum vibration absorber configured as a tuned mass damper as well as an autoparametric system.

Liquid Dynamic Absorbers for Ropeway Carriers and Ships

1999 ◽  
Author(s):  
Hiroshi Matsuhisa ◽  
Yoshihisa Honda
Keyword(s):  
Natural Frequency ◽  
Damping Coefficient ◽  
Experimental Investigations ◽  
Suspension Bridges ◽  
Vibration Absorbers ◽  
Actual Use ◽  
Dynamic Vibration Absorbers ◽  
Liquid Type ◽  
Small Models ◽  
The Relationship

Abstract After Matsuhisa proved that the wind-induced swing of ropeway carriers could be reduced by dynamic absorbers in 1993, many absorbers have been installed in ropeway carriers. In the actual use of dynamic absorbers composed of a steel moving mass on a arc-shaped track, the tunings of natural frequency and damping coefficient are not easy. Liquid-type dynamic vibration absorbers have advantages of ease of tuning the natural frequency and the damping coefficient. In this study, dynamic absorbers composed of liquid (water or viscous liquid) in V-shaped or U-shaped pipes were investigated. The natural frequency can be easily adjusted by the amount of water. The damping coefficient can be adjusted by nozzles at the terminals of pipe, an orifice or a net in liquid and by the viscosity of liquid. The reduction of rolling of gondola lifts, ships and cable suspension bridges by the liquid dynamic absorbers were investigated theoretically. The formula to predict the effectiveness of the absorber was derived. The relationship between the effectiveness of the absorber and its location and shape was discussed. The experimental investigations on the swing of pendulum, the roll of ships and flutter of cable suspension bridges were carried out by means of small models. It was found that the absorbers could reduce the rolling very well and it would be possible to install to the real gondolas, ships and cable suspension bridges.

Sequential design of two orthogonal dynamic vibration absorbers in a pendulum based on stability maximization

2012 ◽  
Vol 226 (11) ◽  
pp. 2645-2655 ◽  
Author(s):  
LD Viet
Keyword(s):  
Tangential Direction ◽  
Normal Direction ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Linear Dynamic ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers ◽  
Small Benefit ◽  
The Stability

A dynamic vibration absorber moving in the tangential or in the normal direction of a pendulum’s orbit can reduce the free vibration of the pendulum. This article discusses the problem of a pendulum structure attached with two dynamic vibration absorbers moving orthogonally at the same time. The analytical optimization is proposed to be done in two steps, in which the parameters of the linear dynamic vibration absorber moving in tangential direction and the non-linear dynamic vibration absorber moving in normal direction are chosen sequentially based on the stability maximization criterion. The analytical analysis shows that the two-dynamic vibration absorber scheme has small benefit in comparison with the single-dynamic vibration absorber scheme. The analytical conclusions are verified by numerical calculations. Although the conclusion of the article is unexpected, it is important in practice because the two-dynamic vibration absorber arrangement can be excluded in the design.

scholarly journals Optimal positions of translational vibration absorbers in vibroisolation of mechanical press

2019 ◽  
Vol 285 ◽  
pp. 00008
Author(s):  
Waldemar Łatas
Keyword(s):  
Rigid Body ◽  
Excitation Frequency ◽  
Harmonic Excitation ◽  
Vibration Absorbers ◽  
Linear Dynamic ◽  
Translational Vibration ◽  
The Press ◽  
Mechanical Press ◽  
Dynamic Vibration Absorbers ◽  
Excitation Force

The paper deals with the problem of optimizing the positions of dynamic vibration absorbers in a mechanical press subjected to harmonic excitation force. Assuming flat motion of a rigid body and small vibrations, a discrete linear dynamic model of the press with absorbers is constructed. Using the results of numerical calculations, the optimal positions of the single or two vibration absorbers tuned to the excitation frequency, for different direction of excitation force, are obtained.

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