State-Switched Absorber for Vibration Control of Point-Excited Beams

2000 ◽  
Author(s):  
Kenneth A. Cunefare
Keyword(s):  
Dynamical System ◽  
Vibration Control ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Spring Element ◽  
Current State ◽  
Resonance Frequencies ◽  
Spectral Components ◽  
Improved Performance ◽  
Force Excitation

Abstract A system that has the capability to make instantaneous changes in its mass, stiffness, or damping may be termed a state-switchable dynamical system. Such a system will display different dynamical responses dependent upon its current state. State-switchable stiffness may be practically obtained through the control of the termination impedance of piezoelectric stiffness elements. If such a switchable stiffness element is incorporated as part of the spring element of a vibration absorber, the change in stiffness causes a change in the resonance frequencies of the system, thereby instantaneously ‘retuning’ the state-switched absorber to a new frequency. In between state switches, the operation of such a device is passive, being fundamentally a passive vibration absorber. This concept has improved performance over classical passive vibration absorbers or dampers, particularly for disturbances with multiple spectral components. This paper considers the application of such a device for the purpose of vibration control on beams subjected to harmonic point-force excitation.

Numerical and Experimental Studies of Pendulum Dynamic Vibration Absorber for Structural Vibration

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Seon Il Ha ◽  
Gil Ho Yoon
Keyword(s):  
Experimental Studies ◽  
Point Of View ◽  
Structural Vibration ◽  
Vibration Absorber ◽  
Square Root ◽  
Vibration Absorbers ◽  
Structural Vibrations ◽  
Dynamic Vibration Absorber ◽  
Dynamic Vibration ◽  
Resonance Frequencies

Abstract This research presents a pendulum dynamic vibration absorber (PDVA) consisting of a spring and a mass in order to attenuate structural vibrations at two frequencies of hosting structure. It is a convention to attach several dynamic absorbers to hosting structure for the sake of the attenuations of structural vibrations at multiple frequencies with enlarged bandwidth and often it increases the total mass and the installation cost. Therefore, the reduction of the number of vibration absorbers for multiple excitation frequencies is an important issue from an engineering point of view. To resolve these difficulties, this study proposes to adopt the vibration absorber framework of the spring-mass vibration as well as the pendulum vibration simultaneously with the present PDVA system. It is composed of a spring and a mass but being allowed to swing circumferentially, the structural vibrations at the two resonance frequencies, i.e., the square root of stiffness over mass and the square root of a length over gravidity, can be simultaneously attenuated. As the length of the spring of the present PDVA is varied, the effective ranges for the pendulum dynamic vibration absorber become widen. To prove the concept of the present PDVA, this research conducts several numerical simulations and experiments.

Experimental Vibration Control of a Two-Degree of Freedom, State-Switched Absorber System

2002 ◽  
Author(s):  
Mark H. Holdhusen ◽  
Kenneth A. Cunefare
Keyword(s):  
Vibration Control ◽  
Vibration Suppression ◽  
Effective Bandwidth ◽  
Vibration Absorbers ◽  
Lumped Mass ◽  
Tuned Vibration Absorbers ◽  
Resonance Frequencies ◽  
Magneto Rheological ◽  
Theoretical Simulations ◽  
Two Degree Of Freedom

A State-Switched Absorber (SSA) is a device capable of instantaneously changing its stiffness, thus it can switch between resonance frequencies, increasing its effective bandwidth as compared to classical tuned vibration absorbers for vibration control. Previous theoretical simulations show that for a system subjected to a multi-harmonic disturbance, using an appropriate logic for switching states, the SSA reduces vibration more effectively than classical tuned vibration absorbers (TVA). This paper considers the experimental performance of the SSA for vibration suppression of an elastically mounted lumped mass base. State switching is achieved using magneto-rheological fluid to connect or disconnect a coil spring in parallel with other coil springs. The stiffness state is controlled by applying or removing a magnetic field across of the MR fluid. Experiments were performed over a range of forcing and tuning frequencies. The SSA system, optimally tuned, outperformed the optimal classical TVA system for all combinations of forcing frequencies.

scholarly journals Some Recent Developments in Adaptive Tuned Vibration Absorbers/Neutralisers

2006 ◽  
Vol 13 (4-5) ◽  
pp. 531-543 ◽  
Author(s):  
Michael J. Brennan
Keyword(s):  
Vibration Control ◽  
Narrow Band ◽  
Notch Filter ◽  
Variable Stiffness ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
The Past ◽  
Tuned Vibration Absorbers ◽  
Control Scheme ◽  
Recent Developments

The vibration absorber has been used for vibration control purposes in many sectors of engineering from aerospace, to automotive to civil, for the past 100 years or so. A limitation of the device, however, is that it acts like a notch filter, only being effective over a narrow band of frequencies. Recent developments have overcome this limitation by making it possible to tune the device over a range of frequencies. This has been achieved by incorporating a variable stiffness element that can be adjusted in real-time. In this paper, some ways in which stiffness change can be achieved in practice are reviewed and some examples of prototype adaptive tuned vibration absorbers (ATVAs) are described. A simple control scheme to automatically tune an ATVA is also presented.

Dual-mass flywheels with tuned vibration absorbers for application in heavy-duty truck powertrains

2020 ◽  
Vol 234 (10-11) ◽  
pp. 2500-2508 ◽  
Author(s):  
Lina Wramner
Keyword(s):  
Combustion Engine ◽  
Vibration Absorber ◽  
Torsional Vibrations ◽  
Vibration Absorbers ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Tuned Vibration Absorbers ◽  
Resonance Frequencies ◽  
Tuning Frequency ◽  
Tuned Vibration Absorber

As the heavy-duty combustion engine development goes towards lower rotational speeds and higher cylinder pressures, the torsional vibrations increase. There is therefore a need to identify and study new types of vibration absorbers that can reduce the level of torsional vibrations transmitted from the engine to the gearbox. In this work, the concept of a dual-mass flywheel combined with a tuned vibration absorber is analysed. The tuned vibration absorber efficiently reduces the vibration amplitudes for engine load frequencies near the tuning frequency, but it also introduces an additional resonance into the system. By placing the tuned vibration absorber on an intermediate flange between the two dual-mass flywheels, the introduced resonance frequency will be lower than the tuning frequency and a resonance in operating engine speed range can be avoided. Numerical simulations are used to show how the torsional vibration amplitudes in a heavy-duty truck powertrain are affected by the tuned vibration absorber and how the different parameters of the tuned vibration absorber and the dual-mass flywheel affect the torsional vibrations and the resonance frequencies.

scholarly journals Optimizations of distributed dynamic vibration absorbers for suppressing vibrations in plates

2018 ◽  
Vol 37 (4) ◽  
pp. 1188-1200 ◽  
Author(s):  
Xuezhi Zhu ◽  
Zhaobo Chen ◽  
Yinghou Jiao
Keyword(s):  
Vibration Control ◽  
Optimization Problems ◽  
Mode Shapes ◽  
Vibration Absorber ◽  
Superposition Method ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Plate Structures ◽  
Dynamic Vibration ◽  
Dynamic Vibration Absorbers

Dynamic vibration absorber is an ideal device for vibration control at specific frequencies. In order to get a robust vibration control performance, multiple or distributed dynamic vibration absorbers are usually used for suppressing vibrations in plate structures. Optimization methods for the single dynamic vibration absorber in various vibration systems had been proposed many years ago. However, the analytical optimization solutions with respect to the distributed dynamic vibration absorbers for the plate structures have not been found. In this paper, the optimization problems of the distributed dynamic vibration absorbers for suppressing vibrations in plates are studied. Vibration equations of the plate carrying distributed dynamic vibration absorbers are established using modal superposition method. The similarities of vibration shapes of the dynamic vibration absorbers and mode shapes of the plate are revealed. According to the characteristics of the vibration shapes of dynamic vibration absorbers, the vibration equations of the plate carrying distributed dynamic vibration absorbers are transformed into a form of equations of a two degree of freedom system. The analytical optimization formulas of the distributed dynamic vibration absorbers for suppressing vibrations in plates are derived by applying the fixed-points theory. The effectiveness of the optimization formulas is verified through numerical simulations. The simulation results also show that a brilliant multi-mode vibration control can be realized by using the optimized distributed dynamic vibration absorbers.

VIBRATION CONTROL OF SLENDER STRUCTURES WITH OPTIMIZED LIQUID COLUMN VIBRATION ABSORBERS

2019 ◽  
Author(s):  
Jéssica Carolina Barbosa Vieira ◽  
Thiago da Silva ◽  
Carlos Alberto Bavastri
Keyword(s):  
Vibration Control ◽  
Liquid Column ◽  
Vibration Absorbers ◽  
Slender Structures

Vibration control using a beam-like adaptive tuned vibration absorber with an actuator-incorporated mass element

2009 ◽  
Vol 223 (7) ◽  
pp. 1555-1567 ◽  
Author(s):  
P Bonello ◽  
K H Groves
Keyword(s):  
Vibration Control ◽  
Effective Mass ◽  
Tuning Range ◽  
Excitation Frequency ◽  
Vibration Absorber ◽  
Time Varying ◽  
Additional Advantage ◽  
Expected Performance ◽  
Vibration Attenuation ◽  
Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) can retune itself in response to a time-varying excitation frequency, enabling effective vibration attenuation over a range of frequencies. For a wide tuning range the ATVA is best realized through the use of a beam-like structure whose mechanical properties can be adapted through servo-actuation. This is readily achieved either by repositioning the beam supports (‘moveable-supports ATVA’) or by repositioning attached masses (‘moveable-masses ATVA’), with the former design being more commonly used, despite its relative constructional complexity. No research to date has addressed the fact that the effective mass of such devices varies as they are retuned, thereby causing a variation in their attenuation capacity. This article derives both the tuned frequency and effective mass characteristics of such ATVAs through a unified non-dimensional modal-based analysis that enables the designer to quantify the expected performance for any given application. The analysis reveals that the moveable-masses concept offers significantly superior vibration attenuation. Motivated by this analysis, a novel ATVA with actuator-incorporated moveable masses is proposed, which has the additional advantage of constructional simplicity. Experimental results from a demonstrator correlate reasonably well with the theory, and vibration control tests with logic-based feedback control demonstrate the efficacy of the device.

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