On Adaptive-Passive Vibration Suppression Using Distributed-Parameter Absorbers

2000 ◽  
Author(s):  
Nader Jalili
Keyword(s):  
Vibration Suppression ◽  
Excitation Frequency ◽  
Wide Band ◽  
Distributed Parameter ◽  
Vibration Absorber ◽  
Frequency Bandwidth ◽  
Lumped Mass ◽  
Adaptive Capability ◽  
Active Vibration ◽  
Tuning Strategy

Abstract A semi-active vibration absorber with adaptive capability is presented to improve wide band vibration suppression characteristics of harmonically excited structures. The absorber subsection consists of a double-ended cantilever beam carrying an intermediate lumped mass. The adaptive capability is achieved through concurrent adjustment of the position of the moving mass, along the beam, to comply with the desired optimal performance. If such an absorber is attached to a vibrating body, it effectively absorbs vibrations at all frequencies that belong to the absorber frequency bandwidth. Numerical simulations are provided to verify the effectiveness of the proposed absorption scheme. It is shown that the tuning strategy tries to follow and match the absorber natural frequency with the excitation frequency. The optimally tuned absorber provides considerable vibration suppression improvement over the passive and de-tuned absorbers, for wide band excitation disturbances.

Adaptive-passive structural vibration attenuation using distributed absorbers

2002 ◽  
Vol 216 (3) ◽  
pp. 223-235 ◽  
Author(s):  
N Jalili ◽  
E Esmailzadeh
Keyword(s):  
Vibration Suppression ◽  
Sufficient Conditions ◽  
Structural Vibration ◽  
Dynamic Vibration Absorber ◽  
Vibration Attenuation ◽  
Adaptive Capability ◽  
On Line ◽  
Lumped Masses ◽  
Necessary And Sufficient ◽  
Tuning Strategy

A distributed dynamic vibration absorber with adaptive capability is presented to improve vibration suppression characteristics of harmonically excited structures. A double-ended cantilever beam carrying intermediate lumped masses forms the absorber subsection. The adaptive capability is achieved through concurrent adjustment of the positions of the moving masses, along the beam, to comply with the desired optimal performance. The necessary and sufficient conditions for the existence of periodic oscillatory behaviour, along with some physical bounds placed on the absorber parameters, form a constrained optimization problem for the optimum tuning strategy. Through numerical simulations it is shown that adaptive tuning is achieved by the variation of tuning mass locations such that the first-mode natural frequency is modulated on-line. The optimally tuned absorber provides considerable vibration suppression improvement over the passive and detuned absorbers.

Tunable Active Vibration Absorber: The Delayed Resonator

1995 ◽  
Vol 117 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Nejat Olgac ◽  
Brian Holm-Hansen
Keyword(s):  
Transient Absorption ◽  
A Priori ◽  
Excitation Frequency ◽  
Vibration Absorber ◽  
Primary System ◽  
Active Vibration ◽  
Absorption Performance ◽  
Primary Focus ◽  
Novel Concept ◽  
Stability Issues

This paper elaborates upon a novel concept, the Delayed Resonator, a tunable active vibration absorber. This technique uses a control which has a time delayed feedback of the absorber mass displacement. The substance of this process is in that the absorber completely removes oscillations from the primary structure. Two very strong features that should be mentioned are: (a) the excitation frequency range can vary over a semi-infinite interval, and (b) the absorber can be tuned in real time. These are the unique characteristics of the technique distinguishing it from the others. Stability issues of the primary system combined with the Delayed Resonator are addressed following Nyquist and root locus methods. In particular, the absorption performance for cases with time varying excitation frequency is studied. The primary focus of this paper is on the analysis of transient absorption behavior of the Delayed Resonator during its tuning. An example case is provided which considers a step change in the excitation frequency. A well-pronounced manifestation of the tunability feature of the Delayed Resonator is observed. The superiority of the Delayed Resonator absorber over the conventional a priori tuned absorbers is also demonstrated.

scholarly journals Friction-Induced Vibration Suppression via the Tuned Mass Damper: Optimal Tuning Strategy

Lubricants ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 100
Author(s):  
Jia Lin Hu ◽  
Giuseppe Habib
Keyword(s):  
Vibration Suppression ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Dynamic Vibration Absorber ◽  
Restoring Force ◽  
Stick Slip ◽  
Optimal Tuning ◽  
Dynamic Vibration ◽  
Tuning Strategy ◽  
Friction Induced Vibration

Friction-induced vibrations are a significant problem in various engineering applications, while dynamic vibration absorbers are an economical and effective tool for suppressing various kinds of vibrations. In this study, the archetypal mass-on-moving-belt model with an attached dynamic vibration absorber was considered. By adopting an analytical procedure, the optimal tuning of the absorber’s parameters was defined. Furthermore, the bifurcations occurring at the loss of stability were analytically investigated; this analysis illustrated that a properly chosen nonlinearity in the absorber’s stiffness permits controlling the supercritical or subcritical character of the bifurcation. However, a numerical analysis of the system’s dynamics, despite confirming the analytical results, also illustrated that the system’s global behavior is only slightly affected by the bifurcation character. Indeed, a dynamic vibration absorber possessing a perfectly linear restoring force function seems to provide the optimal performance; namely, it minimizes the velocity range for which stick–slip oscillations exists.

scholarly journals Optimal Active Vibration Absorber: Design and Experimental Results

1995 ◽  
Vol 117 (2) ◽  
pp. 165-171 ◽  
Author(s):  
G. Lee-Glauser ◽  
Jer-Nan Juang ◽  
J. L. Sulla
Keyword(s):  
Vibration Suppression ◽  
Phase 1 ◽  
Evolutionary Model ◽  
Structural Vibration ◽  
Vibration Absorber ◽  
Resonant Amplitude ◽  
Acceleration Feedback ◽  
Active Vibration ◽  
Langley Research Center ◽  
And Control

An optimal active vibration absorber can provide guaranteed closed-loop stability and control for large flexible space structures with collocated sensors/actuators. The active vibration absorber is a second-order dynamic system which is designed to suppress any unwanted structural vibration. This can be designed with minimum knowledge of the controlled system. Two methods for optimizing the active vibration absorber parameters are illustrated: minimum resonant amplitude and frequency matched active controllers. The Controls-Structures Interaction Phase-1 Evolutionary Model at the NASA Langley Research Center is used to demonstrate the effectiveness of the active vibration absorber for vibration suppression. Performance is compared numerically and experimentally using acceleration feedback.

scholarly journals Active Vibration Absorber for a Continuous Structure Model

2021 ◽  
Author(s):  
Carlos Gianpaul Rincón ◽  
Jorge Alencastre ◽  
Richard Rivera
Keyword(s):  
Cantilever Beam ◽  
Excitation Frequency ◽  
Element Model ◽  
Continuous Model ◽  
Dynamical Behaviour ◽  
Electrical Circuit ◽  
Vibration Absorber ◽  
Piping System ◽  
Primary System ◽  
Active Vibration

The reduction of mechanical vibrations is field of continuous research in engineering in order to reduce damage and improve the performance of structures, machinery, piping and others systems, when they are in presence of dynamical forces. In this sense, different alternatives have been proposed over time, the active vibration absorber highlights as an alternative which can absorb the vibration from a primary system for different excitation frequency in real time. In this study, an active vibration absorber has been modelled as an electromechanical device composed of a 1-DOF model for the absorber and an equivalent electrical circuit for the electromagnetic actuator. It was implemented in a real structure represented by a cantilever beam continuous model, which is the most accurate model that can be used. A set of differential equations which represent the dynamical behaviour of the cantilever beam implemented with the active vibration absorber was obtained from the complete model and it was simulated in Matlab Simulink®. An application of the active vibration absorber for an industry piping system based on the finite element model formulation is presented and developed. Results indicate that the active vibration absorber is able to significantly reduce the vibrations amplitude of the primary system, especially in resonance conditions, for a discrete frequency range. The analytic model and procedure developed here can easily widespread to any more complex primary system.

scholarly journals Research on vibration reduction performance of dynamic vibration absorber based on damping characteristic of a new material

2020 ◽  
Vol 12 (11) ◽  
pp. 168781402096159
Author(s):  
Weizhi Song ◽  
Zhien Liu ◽  
Chihua Lu ◽  
Yongchao Li ◽  
Bin Li
Keyword(s):  
Frequency Band ◽  
Vibration Reduction ◽  
Excitation Frequency ◽  
Vibration Absorber ◽  
Dynamic Vibration Absorber ◽  
Controlled System ◽  
Resonance Point ◽  
Dynamic Vibration ◽  
New Material ◽  
Active Vibration

The absorbing effect of traditional dynamic vibration absorber (TDVA) is satisfactory only when the natural frequency is close to the excitation frequency. For this defect, a semi-active vibration absorber is designed with magnetorheological elastomer (MRE) as a stiffness element, that its stiffness can be controlled by magnetic field, to widen the frequency band of the absorber. Theory and experiments show that reducing the damp of the absorber can improve the performance of the absorber at the anti-resonance point, but it will cause the vibration of the controlled system at the new resonance point, which caused by the addition of a DVA, to be more intense. For this problem, the compatibilizer: silane coupling agent KH570, is added to the preparation of MRE to reduce material damping, at the same time, the stiffness control strategy is used to eliminate the resonance of the controlled system caused by the addition of DVA. The final experimental results show that the frequency band of vibration reduction has been broadened effectively and the vibration reduction performance has been improved considerably. Moreover, the resonance has been eliminated very well.

Effects of nonlinear interactions of flexural modes on the performance of a beam autoparametric vibration absorber

2019 ◽  
Vol 26 (7-8) ◽  
pp. 459-474
Author(s):  
Saeed Mahmoudkhani ◽  
Hodjat Soleymani Meymand
Keyword(s):  
Frequency Response ◽  
Internal Resonance ◽  
Continuation Method ◽  
Harmonic Balance Method ◽  
Vibration Absorber ◽  
Primary System ◽  
Lumped Mass ◽  
Response Curves ◽  
Internal Resonances ◽  
The One

The performance of the cantilever beam autoparametric vibration absorber with a lumped mass attached at an arbitrary point on the beam span is investigated. The absorber would have a distinct feature that in addition to the two-to-one internal resonance, the one-to-three and one-to-five internal resonances would also occur between flexural modes of the beam by tuning the mass and position of the lumped mass. Special attention is paid on studying the effect of these resonances on increasing the effectiveness and extending the range of excitation amplitudes at which the autoparametric vibration absorber remains effective. The problem is formulated based on the third-order nonlinear Euler–Bernoulli beam theory, where the assumed-mode method is used for deriving the discretized equations of motion. The numerical continuation method is then applied to obtain the frequency response curves and detect the bifurcation points. The harmonic balance method is also employed for detecting the type of internal resonances between flexural modes by inspecting the frequency response curves corresponding to different harmonics of the response. Parametric studies on the performance of the absorber are conducted by varying the position and mass of the lumped mass, while the frequency ratio of the primary system to the first mode of the beam is kept equal to two. Results indicated that the one-to-five internal resonance is especially responsible for the considerable enhancement of the performance.

Design of a slender turning cutting tool via a vibration absorber equipped with piezoelectric ceramic

2021 ◽  
pp. 107754632110144
Author(s):  
Yiqing Yang ◽  
Haoyang Gao ◽  
Qiang Liu
Keyword(s):  
Piezoelectric Ceramic ◽  
Cutting Tool ◽  
Vibration Suppression ◽  
Equations Of Motion ◽  
Electrical Energy ◽  
Diameter Ratio ◽  
Vibration Absorber ◽  
Machined Surface ◽  
Structural Part ◽  
Machined Surface Roughness

Turning cutting tool with large length–diameter ratio has been essential when machining structural part with deep cavity and in-depth hole features. However, chatter vibration is apt to occur with the increase of tool overhang. A slender turning cutting tool with a length–diameter ratio of 7 is developed by using a vibration absorber equipped with piezoelectric ceramic. The vibration absorber has dual functions of vibration transfer to the absorber mass and vibration conversion to the electrical energy via the piezoelectric effect. Equations of motion are established considering the dual damping from the piezoelectric ceramic and rubber gasket. The equivalent damping of piezoelectric ceramic is derived, and the geometries are optimized to achieve optimal vibration suppression. The modal analysis demonstrates that the cutting tool with the vibration absorber can reach 80.1% magnitude reduction. Machining tests are carried out in the end. The machining acceleration and machined surface roughness validate the vibration suppression of the VA, and the output voltage by the piezoelectric ceramic demonstrates the ability of vibration sensing.

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