0
Research Papers

Transformer Eddy Current Dampers for the Vibration Control

[+] Author and Article Information
Andrea Tonoli

Mechatronics Laboratory, Mechanics Department,  Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italyandrea.tonoli@polito.it

Nicola Amati

Mechatronics Laboratory, Mechanics Department,  Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italynicola.amati@polito.it

Mario Silvagni

Mechatronics Laboratory, Mechanics Department,  Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino, Italymario.silvagni@polito.it

J. Dyn. Sys., Meas., Control 130(3), 031010 (May 12, 2008) (9 pages) doi:10.1115/1.2907358 History: Received October 16, 2006; Revised November 27, 2007; Published May 12, 2008

Eddy current dampers are promising for the passive and semiactive vibration control of mechanical structures. Among them, the “motional” types are based on Lorentz forces between a moving conductor and a stationary magnetic field. On the contrary, “transformer” ones exploit electromagnetic forces varying the reluctance of the magnetic circuit due to the motion of a part of the damper. Considering the simplicity of the layout, transformer configurations seem to be very promising as alternative to traditional rubber or squeeze film dampers to control the lateral vibration of rotating machines. The aim of the present paper is to investigate the dynamic behavior of transformer eddy current dampers integrated in a mechanical structure. The electromechanical system is modeled using the Lagrange approach in terms of the magnetic flux linkages in the electromagnets. The mathematical models have been experimentally validated using two test benches with different layouts and geometrical characteristics of the magnetic circuit. The modeling approach allows to propose a design procedure of this type of damper.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Sketch of a two electromagnet “transformer” eddy current damper

Grahic Jump Location
Figure 2

(a) Mechanical impedance of a transformer eddy current damper parallel to a spring of stiffness Km and (b) mechanical equivalent

Grahic Jump Location
Figure 3

Single degree of freedom test bench: (a) sketch, (b) test bench, and (c); damper’s electromagnetic circuit that evidences the active (A) and passive (P) volumes of the coil’s copper

Grahic Jump Location
Figure 4

Comparison between the analytical and the experimental inductance of each electromagnet (reference to the single degree of freedom test bench)

Grahic Jump Location
Figure 5

Mechanical impedance of the electromagnetic actuator for different values of the voltage supply (V) (a) and of the additional resistance (Radd) (b). The curves are obtained by numerical simulations on the base of the single degree of freedom test bench (Table 1).

Grahic Jump Location
Figure 6

Damping factor as function of the voltage supply and additional resistance. Data referred to the single degree of freedom test bench (Table 1).

Grahic Jump Location
Figure 7

Flexible beam test bench: (a) sketch, (b) test bench, and (c) damper’s electromagnetic circuit. A and P indicate the active and passive volumes.

Grahic Jump Location
Figure 8

Inductance of each electromagnet (reference to the U-shaped electromagnets of the flexible beam test bench)

Grahic Jump Location
Figure 9

Comparison between the numerical and the experimental transfer functions (FRF): (a) single degree of freedom test bench and (b) flexible beam test bench

Grahic Jump Location
Figure 10

Single degree of freedom test bench; time history of the displacement q for different maximum displacements qmax at constant voltage V=0.75V

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In