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.

Designs for an adaptive tuned vibration absorber with variable shape stiffness element

2005 ◽  
Vol 461 (2064) ◽  
pp. 3955-3976 ◽  
Author(s):  
Philip Bonello ◽  
Michael J Brennan ◽  
Stephen J Elliott ◽  
Julian F.V Vincent ◽  
George Jeronimidis
Keyword(s):  
Vibration Control ◽  
Shape Change ◽  
Excitation Frequency ◽  
Variable Stiffness ◽  
Experimental Results ◽  
Vibration Absorber ◽  
Time Varying ◽  
Variable Geometry ◽  
Curved Beams ◽  
Tuned Vibration Absorber

An adaptive tuned vibration absorber (ATVA) with a smart variable stiffness element is capable of retuning itself in response to a time-varying excitation frequency, enabling effective vibration control over a range of frequencies. This paper discusses novel methods of achieving variable stiffness in an ATVA by changing shape, as inspired by biological paradigms. It is shown that considerable variation in the tuned frequency can be achieved by actuating a shape change, provided that this is within the limits of the actuator. A feasible design for such an ATVA is one in which the device offers low resistance to the required shape change actuation while not being restricted to low values of the effective stiffness of the vibration absorber. Three such original designs are identified: (i) A pinned–pinned arch beam with fixed profile of slight curvature and variable preload through an adjustable natural curvature; (ii) a vibration absorber with a stiffness element formed from parallel curved beams of adjustable curvature vibrating longitudinally; (iii) a vibration absorber with a variable geometry linkage as stiffness element. The experimental results from demonstrators based on two of these designs show good correlation with the theory.

Whirling-Beam Self-Tuning Vibration Absorber

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Douglas Ivers ◽  
Robert Wilson ◽  
Donald Margolis
Keyword(s):  
Excitation Frequency ◽  
Vibration Absorber ◽  
Input Frequency ◽  
Fixed Frequency ◽  
Physical Motion ◽  
Self Tuning ◽  
Proper Design ◽  
Specific Frequency ◽  
Frequency Changes ◽  
Tuned Vibration Absorber

A classic tuned vibration absorber (TVA) is a device that, when attached to a structure, will greatly reduce the motion of the attachment at a specific excitation frequency. When a fixed frequency input is present, a TVA can be manufactured for the specific frequency input. When the input frequency changes during the course of operation, then an active adaptive TVA can be used where sensors, signal conditioning, and power are provided so that the tuned frequency can be varied over some range. A self-tuning vibration absorber (STVA) is a device that uses energy from the vibrating structure to produce some physical motion that changes the tuned frequency of the device. Through proper design, the tuned frequency will change in the appropriate direction and then stop changing when the tuned frequency matches the input frequency. This paper addresses the physics of one realization of a STVA and shows both analytical and experimental results.

scholarly journals Study of vibration control using laboratory test rig of wind turbine tower-nacelle system with MR damper based tuned vibration absorber

2016 ◽  
Vol 64 (2) ◽  
pp. 347-359 ◽  
Author(s):  
P. Martynowicz
Keyword(s):  
Vibration Control ◽  
Wind Turbine ◽  
Sliding Mode ◽  
Mr Damper ◽  
Open Loop ◽  
Laboratory Model ◽  
Vibration Absorber ◽  
Fatigue Wear ◽  
Wind Turbine Tower ◽  
Tuned Vibration Absorber

Abstract Wind turbine tower dynamic stress is related to the fatigue wear and reliability of the whole wind turbine structure. This paper deals with the problem of tower vibration control using a specially designed and built laboratory model. The considered wind turbine tower-nacelle model consists of a vertically arranged stiff rod (representing the tower), and a system of steel plates (representing nacelle and turbine assemblies) fixed at its top. The horizontally aligned tuned vibration absorber (TVA) with magnetorheological (MR) damper is located also at the top of the rod (in nacelle system). Force excitation sources applied horizontally to the tower itself and to the nacelle were both considered. The MR damper real-time control algorithms, including ground hook control and its modification, sliding mode control, linear and nonlinear (cubic and square root) damping, and adaptive solutions are compared to the open-loop case with various constant MR damper input current values and system without MR TVA (i.e., MR TVA in “locked” state). Comprehensive experimental analyses and their results are presented.

scholarly journals Nonlinear Optimal-Based Vibration Control of a Wind Turbine Tower Using Hybrid vs. Magnetorheological Tuned Vibration Absorber

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5145
Author(s):  
Paweł Martynowicz
Keyword(s):  
Vibration Control ◽  
Wind Turbine ◽  
Energy Demand ◽  
Control Method ◽  
Vibration Absorber ◽  
Real Time Control ◽  
Time Control ◽  
Working Space ◽  
Wind Turbine Tower ◽  
Tuned Vibration Absorber

This paper presents an implementation of a nonlinear optimal-based wind turbine tower vibration control method. An NREL 5.0 MW tower-nacelle model equipped with a hybrid tuned vibration absorber (HTVA) is analysed against the model equipped with a magnetorheological TVA (MRTVA). For control purposes, a 3 kN active actuator in parallel with a passive TVA is used in the HTVA system, while an MR damper is built in the MRTVA instead of a viscous damper, as in a standard TVA. All actuator force constraints are embedded in the implemented nonlinear control techniques. By employing the Pontryagin maximum principle, the nonlinear optimal HTVA control proposition was derived along with its simplified revisions to avoid a high computational load during real-time control. The advantage of HTVA over MRTVA in vibration attenuation is evident within the first tower bending frequency neighbourhood, with HTVA also requiring less working space. Using the appropriate optimisation fields enabled an 8-fold reduction of HTVA energy demand along with a (further) 29% reduction of its working space while maintaining a significant advantage of HTVA over the passive TVA. The obtained results are encouraging for the assumed mass ratio and actuator force limitations, proving the effectiveness and validity of the proposed approaches.

Vibration control of wind turbine tower-nacelle model with magnetorheological tuned vibration absorber

2015 ◽  
Vol 23 (20) ◽  
pp. 3468-3489 ◽  
Author(s):  
Paweł Martynowicz
Keyword(s):  
Vibration Control ◽  
Wind Turbine ◽  
Sliding Mode ◽  
Mr Damper ◽  
Numerical Analyses ◽  
Comsol Multiphysics ◽  
Laboratory Model ◽  
Vibration Absorber ◽  
Wind Turbine Tower ◽  
Tuned Vibration Absorber

Wind turbine tower dynamic load is related to the fatigue and reliability of the structure. This paper deals with the problem of tower vibration control using specially designed and built numerical and laboratory model. The regarded wind turbine tower-nacelle model consists of vertically arranged stiff rod (representing the tower), and a stiff body fixed at its top representing nacelle assembly that is equipped with horizontally aligned tuned vibration absorber (TVA) with magnetorheological (MR) damper. To model tower-nacelle dynamics, Comsol Multiphysics finite element method environment was used. For time and frequency domain numerical analyses (including first and second bending modes of vibration) of system with TVA and MR damper models, MATLAB/Simulink environment was used with Comsol Multiphysics tower-nacelle model embedded. Force excitation sources applied horizontally to the nacelle, and to the tower itself were both considered. The MR damper real-time control algorithms, including ground hook control and its modification, sliding mode control, linear and nonlinear (cubic and square root) damping, and adaptive solutions are compared to the open-loop case with various constant MR damper input current values and system without MRTVA (i.e. MRTVA in ‘locked’ state). Comprehensive numerical analyses results are presented along with Vensys 82 full-scale tower-nacelle model validation. Finally, preliminary results of laboratory tests are included.

Active-Adaptive Vibration Absorbers and its Vibration Attenuation Performance

2013 ◽  
Vol 312 ◽  
pp. 262-267 ◽  
Author(s):  
Chao Peng ◽  
Xing Long Gong
Keyword(s):  
Dynamic Properties ◽  
Damping Ratio ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Damping Effect ◽  
Vibration Attenuation ◽  
Active Vibration ◽  
Working Frequency ◽  
Vibration Attenuation Performance ◽  
Tuned Vibration Absorber

To improve the working frequency band and the damping effect of vibration absorber, an active-adaptive vibration absorber (AAVA) was presented. The AAVA can be considered as the integration of adaptive tuned vibration absorber (ATVA) and active vibration absorbers (AVA). The principle and the dynamic character of the proposed AAVA were theoretically analyzed. Based on the analysis, a prototype was designed and manufactured. Its dynamic properties and vibration attenuation performances were experimentally investigated. The experimental results demonstrated that the damping ratio of the prototype was significantly reduced by the active force. Consequently, its vibration attenuation capability was significantly improved compared with the ATVA.

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