scholarly journals Active damping of vibrations in elevator cars

1999 ◽  
Vol 6 (1) ◽  
pp. 53-100 ◽  
Author(s):  
A. Hamdy
Keyword(s):  
Active Damping ◽  
Damping Of Vibrations

Active Damping of Vibrations of a Cantilever Beam by Axial Force Control

2007 ◽  
Author(s):  
Thomas Pumho¨ssel ◽  
Horst Ecker
Keyword(s):  
Cantilever Beam ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Open Loop ◽  
Active Damping ◽  
Nonlinear Feedback ◽  
Euler Beam ◽  
Bending Vibrations ◽  
Loop Control ◽  
Damping Of Vibrations

In several fields, e.g. aerospace applications, robotics or the bladings of turbomachinery, the active damping of vibrations of slender beams which are subject to free bending vibrations becomes more and more important. In this contribution a slender cantilever beam loaded with a controlled force at its tip, which always points to the clamping point of the beam, is treated. The equations of motion are obtained using the Bernoulli-Euler beam theory and d’Alemberts principle. To introduce artificial damping to the lateral vibrations of the beam, the force at the tip of the beam has to be controlled in a proper way. Two different methods are compared. One concept is the closed-loop control of the force. In this case a nonlinear feedback control law is used, based on axial velocity feedback of the tip of the beam and a state-dependent amplification. By contrast, the concept of open-loop parametric control works without any feedback of the actual vibrations of the mechanical structure. This approach applies the force as harmonic function of time with constant amplitude and frequency. Numerical results are carried out to compare and to demonstrate the effectiveness of both methods.

Protection of Continuous Structures Against Vibrations by Active Damping

1983 ◽  
Vol 105 (3) ◽  
pp. 374-381
Author(s):  
E. Luzzato ◽  
M. Jean
Keyword(s):  
Control System ◽  
Mechanical Model ◽  
Approximation Problem ◽  
Active Damping ◽  
Simply Supported ◽  
Viscoelastic Structure ◽  
Flexural Vibrations ◽  
Dimension Space ◽  
Damping Of Vibrations ◽  
General Method

In this paper, we deal with the problem of active damping of vibrations of a continuous viscoelastic structure, and a general method of computation of the control system is developed. We define a mechanical model for this structure, the sources of perturbing vibrations, the control system, and different absorption criteria. The problem is set in an infinite dimension space, and an approximation problem is derived in n dimension spaces. Two methods of resolution are proposed for this approximation problem, and the solutions are compared. An example is given for the case of flexural vibrations in beams. Numerical results simulating the behavior of flexural vibrations in a rectangular plate, which is simply supported along the whole boundary, are presented for three different absorption criteria, thus permitting a quick evaluation of the comparative effectiveness of the chosen criteria.

Controllable Truss-Frame Nodes in Semi-Active Damping of Vibrations

2016 ◽  
Vol 101 ◽  
pp. 89-94 ◽  
Author(s):  
Blazej Poplawski ◽  
Cezary Graczykowski ◽  
Łukasz Jankowski
Keyword(s):  
Cantilever Beam ◽  
Control Strategy ◽  
Strain Energy ◽  
Vibration Mode ◽  
Vibration Damping ◽  
Active Damping ◽  
Active Management ◽  
Complex Structures ◽  
Published Research ◽  
Damping Of Vibrations

In recent years, vibration damping strategies based on semi-active management of strain energy have attracted a large interest and were proven highly effective. However, most of published research considers simple one degree of freedom systems or study the same basic example (the first vibration mode of a cantilever beam) with the same control strategy. This contribution focuses on truss-frame nodes with controllable moment-bearing ability. It proposes and tests an approach that allows the control strategy to be extended to more complex structures and vibration patterns.

On the active damping of vibrations using electromagnetic spring

2020 ◽  
pp. 1-14 ◽  
Author(s):  
Maksymilian Bednarek ◽  
Donat Lewandowski ◽  
Krystian Polczyński ◽  
Jan Awrejcewicz
Keyword(s):  
Active Damping ◽  
Damping Of Vibrations
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