A self-tuning electromagnetic vibration absorber with adaptive shunt electronics (original) (raw)
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A tunable electromagnetic vibration absorber: Characterization and application
Journal of Sound and Vibration, 2006
The paper presents a newly designed electromagnetic vibration absorber (EMVA), whose stiffness is on-line tunable. The EMVA is capable of suppressing vibration of the primary system excited by a harmonic force with a variable frequency. The EMVA consists of a clamped-clamped aluminum beam and a permanent magnet that is embedded in the center of the beam and placed between two poles of a C-shaped electromagnet. By varying the current of the electromagnet, stiffness of the EMVA can be adjusted instantaneously such that the absorber frequency can be tuned. A detailed characterization of the EMVA is presented. The effective stiffness of the absorber is determined numerically and validated experimentally. To test its effectiveness in vibration suppression, the EMVA is used to track two types of the exciting frequency variations: multi-step and linear. The response of the absorber mass is used to tune the EMVA to ensure that the absorber frequency equals the exciting frequency. r
Passive Vibration Control via Electromagnetic Shunt Damping
IEEE/ASME Transactions on Mechatronics, 2005
This work will present a new type of passive vibration control technique based on the concept of electromagnetic shunt damping. The proposed technique is similar to piezoelectric shunt damping, as an appropriately designed impedance is shunted across the terminals of the transducer. Theoretical and experimental results are presented for a simple electromagnetic mass spring damper system.
Tuning of a vibration absorber with shunted piezoelectric transducers
Archive of Applied Mechanics, 2014
In order to reduce structural vibrations in narrow frequency bands, tuned mass absorbers can be an appropriate measure. A quite similar approach which makes use of applied piezoelectric elements, instead of additional oscillating masses, are the well-known resonant shunts, consisting of resistances, inductances, and possibly negative capacitances connected to the piezoelectric element. This paper presents a combined approach, which is based on a conventional tuned mass absorber, but whose characteristics can be strongly influenced by applying shunted piezoceramics. Simulations and experimental analyses are shown to be very effective in predicting the behavior of such electromechanical systems. The vibration level of the absorber can be strongly attenuated by applying different combinations of resistant, resonant, and negative capacitance shunt circuits. The damping characteristics of the absorber can be changed by applying a purely resistive or resonant resistant shunt. Additionally, the tuning frequency of the absorber can be adapted to the excitation frequency, using a negative capacitance shunt circuit, which requires only the energy to supply the electric components.
Mechanical tuned vibration absorbers (MTVAs) are devices used to mitigate the vibrations of a structure around one of its eigenfrequencies. By introducing an additional degree of freedom in the structure, MTVAs allow to split the peak of interest in the frequency response in two peaks with lower amplitudes. The design of MTVAs is usually based on the (approximate) equal-peak method proposed by Den Hartog. A closed-form exact solution was however obtained by Asami and Nishihara, for which the two peaks of the frequency response have exactly the same amplitude. Similarly to MTVAs, piezoelectric tuned vibration absorbers (PTVAs) allow to damp efficiently a specific peak of the frequency response. Although a pole placement technique can be used to design such devices, tuning rules are usually based on approximate equal-peak methods which define the optimum values of the resistor and the inductance of the shunt. Very recently, Asami and Nishihara's exact solution has been extended for the equal-peak method to PTVAs by the authors of the present paper. The first contribution of this paper is to illustrate this new optimum design of a series RL piezoelectric shunt on a realistic example. A clamped-free steel plate excited with two piezoelectric actuators and shunted with two piezoelectric transducers is modelled using plate elements (laminates). Non-linearity is then introduced in the host structure, and a new nonlinear PTVA for mitigating the vibrations of the non-linear host structure is proposed. The improvement of damping performances in the presence of structural non-linearties using a non-linear PTVA is illustrated. * Gilles Tondreau, gilles.tondreau@ulb.ac.be.
Adaptive Electromagnetic Vibration Absorber for a Multimode Structure
Strojniški vestnik, 2022
All structures experience vibrations due to external dynamic force excitations such as earthquakes and wind loadings. At resonance, the impact of this natural dynamic force on structures may lead to structural failures. Hence, an absorber is mounted to absorb vibrations from the primary system. Unfortunately, passive tuned mass absorbers can only target a single frequency. Since structural buildings possess multiple modes, an adaptive or tune-able vibration absorber is needed to attenuate the vibration in a multi-degree of freedom (MDOF) system. In this work, an adaptive electromagnetic vibration absorber (AEMVA) is proposed to eliminate the effects of vibrations and is dynamically tuned using electromagnets. By varying the current supplied to the coil, the stiffness of the AEMVA can be adjusted, resulting in a varying absorber frequency. A mathematical description of the AEMVA on a three-story building prototype model building is also presented. The three-story benchmark model was used to demonstrate the effectiveness of AEMVA in absorbing multiple vibration modes, both analytically and experimentally. It is shown that 68.81%, 50.49%, and 33.45% of vibration amplitude reductions were achieved at the first, second, and third modes, respectively.
Adaptive electromagnetic shunt damping
IEEE/ASME Transactions on Mechatronics, 2000
This paper presents a new type of passive vibration control: adaptive electromagnetic shunt damping. We propose a single-mode resonant shunt controller that adapts to environmental conditions using two different adaptation strategies. The first technique is based on minimizing the root mean square (RMS) vibration, while the second minimizes the phase difference between two measurable signals. An experimental comparison shows that relative phase adaptation performs better than the RMS technique.
High Bandwidth Tunability in a Smart Vibration Absorber
Journal of Intelligent Materials Systems and Structures, 2000
The theory of an electrically tunable Terfenol-D vibration absorber is developed in this paper. An overview of magnetostriction including discussion of the DE effect is presented. Experimental results showing agreement with prior art are included that demonstrate electrical control of a magnetostrictive actuator resonant frequency by varying the resonance between 1275 Hz and 1725 Hz. The tunability of the transducer resonant frequency is then implemented to achieve high bandwidth tunability in the performance of a Terfenol-D vibration absorber.
Adaptive Torsional Tuned Vibration Absorber for Rotary Equipment
Vibration
This paper proposes an innovative solution to suppress torsional vibrations in any rotating machinery with a variable frequency of excitation, or a variable natural frequency. The adaptive torsional tuned vibration absorber (ATTVA) was designed using an integrated electromagnetic circuit, which can adapt its natural frequency to match the varying natural frequency of any Multi Degree of Freedom (MDOF) rotating system. A two degree of freedom rotating system was modeled along with the integrated ATTVA using the bond graph modeling technique. Simulation results showed that torsional vibrations can be easily attenuated by controlling the capacitance shunted to the voice coil circuit. The ATTVA was designed, fabricated and evaluated on a test rig in the laboratory. Test results revealed good matching between the mathematical model and the experimental data. Experiments were performed with different configurations of the ATTVA, and the experimental results showed reasonable suppression i...