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Showing papers on "Dynamic Vibration Absorber published in 2000"


Journal ArticleDOI
TL;DR: In this article, a tunable solid-state piezoelectric vibration absorber and an active tuning method were developed and demonstrated, where the effective stiffnesses of these elements were adjusted electrically, using a passive capacitive shunt circuit, to tune the resonance frequency of the device.

257 citations


Journal ArticleDOI
TL;DR: In this article, a piezoelectric inertia actuator is mounted on the cutting tool and acted as a tuned vibration absorber for the suppression of chatter in turning operations.

163 citations


Journal ArticleDOI
TL;DR: In this article, the fundamental analysis tools for a Single-Degree-of-Freedom (SDF) state-switchable device are presented, and the application of such a device for the purpose of vibration control in a 2-DOF system is considered.
Abstract: A system that has the capability to make instantaneous changes in its mass, stiffness, or damping may be termed a state-switchable dynamical system. Such a system will display different dynamical responses dependent upon its current state. For example, state-switchable stiffness may be practically obtained through the control of the termination impedance of piezoelectric stiffness elements. If such a switchable stiffness element is incorporated as part of the spring element of a vibration absorber, the change in stiffness causes a change in the resonance frequencies of the system, thereby instantaneously “retuning” the state-switched absorber to a new frequency. This paper briefly develops the fundamental analysis tools for a Single-Degree-of-Freedom state-switchable device, and then considers the application of such a device for the purpose of vibration control in a 2-DOF system. Simulation results indicate that state-switched vibration absorbers may be advantageous over classical passive tuned vibration...

96 citations


Journal ArticleDOI
TL;DR: In this paper, a sloshing absorber is proposed to control excessive oscillations of a mechanical oscillator in response to an initial displacement, and a numerical simulation procedure is introduced as a computer-aided design tool.

66 citations


Journal ArticleDOI
TL;DR: In this article, the authors analyzed the forced transverse vibrations of an elastically connected double-string complex continuous system and found the general solutions of forced vibrations of strings subjected to arbitrarily distributed continuous loads.

56 citations


Patent
06 Nov 2000
TL;DR: In this article, a toolholder with a dynamic vibration absorber is described, where an absorber mass is compressed between two elastomer supports, utilizing at least one longitudinally movable pressure plate (65, 70) to dynamically tune the toolholder.
Abstract: A tunable toolholder (10) with a dynamic vibration absorber (30) is disclosed wherein an absorber mass (50) is compressed between two elastomer supports (65, 70) utilizing at least one longitudinally movable pressure plate (65, 70) to dynamically tune the toolholder (10).

49 citations


Journal ArticleDOI
TL;DR: In this article, the authors investigate theoretically and experimentally the performance of a recently developed quadratic vibration absorber that is based on the saturation phenomenon and consider the problem o...
Abstract: The authors investigate theoretically and experimentally the performance of a recently developed quadratic vibration absorber that is based on the saturation phenomenon. They consider the problem o...

48 citations


Journal ArticleDOI
TL;DR: In this article, the authors compared the Delayed Resonator (DR) and proportional and derivative (PD) control strategies to suppress undesired oscillations in a single-degree-of-freedom primary structure and an absorber with electromagnetic actuator.
Abstract: The Delayed Resonator (DR) is a recent active vibration absorption technique which uses time delayed position feedback generating ideal resonance feature in a passive vibration absorber. This objective can also be achieved using proportional and derivative (PD) control as well as other more sophisticated routines such as LQR, sliding mode control. In this paper, DR technique is compared with PD, a widely adopted control strategy. Actuator dynamics is taken into account in analyzing the system. An analytical comparison is presented which is followed by an experimental validation of the findings using a single-degree-of-freedom primary structure and an absorber with electromagnetic actuator. Both analytical and experimental results show that the DR and PD implementations can be equally effective in suppressing undesired oscillations. The latter, however, requires a velocity observer, which is an additional complexity beyond the DR feedback structure.

44 citations


Journal ArticleDOI
TL;DR: In this paper, a sensitivity analysis is presented for a novel tuned vibration absorber, which is achieved using partial state feedback with a controlled time delay, and the final structure is optimized to yield minimum M peak of the primary system involved for a given wide band of excitation frequencies.
Abstract: A sensitivity analysis is presented for a novel tuned vibration absorber. The active tuning of the absorber is achieved using partial state feedback with a controlled time delay. The final structure, which is named Delayed Feedback Vibration Absorber (DFVA), is optimized to yield minimum M peak of the primary system involved for a given wide band of excitation frequencies. The optimization is performed over the absorber's structural properties and the feedback control parameters. An optimal tuning over optimally designed passive absorber is conducted first, and separately a collective optimization over both the absorber structure and the control is studied. The assurance of the stability of the time-delayed system, which forms a critical constraint on the optimization, is also discussed, Regardless of the nature of the optimal operation, the parametric variations in the structure can influence the vibration absorption performance significantly, This concern is addressed via a sensitivity analysis. Primarily, the variations on the absorber stiffness and damping properties are studied. The findings of this effort provide tools for determining the acceptable tolerance limits of the absorber properties.

40 citations


Journal ArticleDOI
TL;DR: In this article, a passive non-linear vibration controller for flexible structures has been presented, which consists of a cantilever beam with a tip mass attached to the tip mass as a passive vibration controller.

37 citations


Journal ArticleDOI
TL;DR: In this article, an electrically tunable vibration absorber based on the strong ΔE effect of Terfenol-D has been developed, where the magnetic field is increased from the demagnetized state to magnetic saturation.
Abstract: An electrically tunable vibration absorber based on the strong ΔE effect of Terfenol-D has been developed. A general description of tuned vibration absorbers is presented along with a description of the magnetostrictive effects that make an electrically tunable Terfenol-D vibration aborber function. It is emphasized that the large modulus changes achievable with the proposed magnetostrictive vibration absorber arise as a consequence of the stiffening of the crystal lattice as the magnetic field is increased from the demagnetized state to magnetic saturation. This is in contrast to the small modulus changes often reported in the literature which are achieved by operating smart materials between their open- and short-circuit states. Experimental results are presented that show agreement with prior art and demonstrate control of a magnetostrictive actuator resonant frequency between 1375 Hz and 2010 Hz by electrically varying the elastic modulus of a magnetostrictive material. This operating principle is then implemented to obtain high bandwidth tunability in a Terfenol-D vibration absorber.

Journal ArticleDOI
TL;DR: In this paper, the potential of the piecewise linear vibration absorber in a system subject to narrow band harmonic loading is explored and the absorber parameters needed to produce good designs have been determined and the quality of realized suppression zone is discussed.
Abstract: This paper explores the potential of the piecewise linear vibration absorber in a system subject to narrow band harmonic loading. Such a spring is chosen because the design of linear springs is common knowledge among engineers. The two-degrees-of-freedom system is solved by using the Incremental Harmonic Balance method, and response aspects such as stiffness crossing frequency and jump behaviour are discussed. The effects of mass, stiffness, natural frequency ratios, and stiffness crossing positions on the suppression zone are probed. It is shown that a hardening absorber can deliver a wider bandwidth than a linear one over a range of frequencies. The absorber parameters needed to produce good designs have been determined and the quality of the realized suppression zone is discussed. Design guidelines are formulated to aid the parameter selection process.

Patent
17 Jul 2000
TL;DR: In this paper, a vibration absorber is provided between a wiper frame and a vehicle body frame, which includes a cylinder and a pair of flanges arranged near opposite axial ends of the cylinder.
Abstract: A vibration absorber is provided between a wiper frame and a vehicle body frame The vibration absorber includes a cylinder and a pair of flanges arranged near opposite axial ends of the cylinder The cylinder is fitted in an opening formed in the wiper frame The cylinder has a through hole through which a bolt is inserted One flange is located between the wiper frame and a washer secured to the bolt The other flange is located between the wiper frame and the body frame Each flange has an arched axial cross-sectional shape The flanges reliably absorb axial vibration of the wiper frame

Patent
Keith R. Ptak1
25 Feb 2000
TL;DR: In this article, a torsional spring is used to provide a desired vibratory dampening characteristic for applications, such as pipelines, which may be less susceptible to failure in harsh environments.
Abstract: Vibration absorbers are provided which utilize a torsional spring and a dynamic mass to control vibrations that occur within the structure to which they are attached. Additionally, pipeline systems are provided which utilize such vibration absorbers including a mass and a torsional spring to control the vibrations that occur within the pipeline system. In various embodiments of the present invention, the torsional spring is one or more elastomer elements coupled between the dynamic mass and a support frame to produce a spring force responsive to pivotal rotation of the dynamic mass relative to the support frame. In various embodiments, one or more elastomer elements arranged in series or in parallel may be used as the torsional spring to provide a desired vibratory dampening characteristic for applications, such as pipelines. Use of such torsional springs may provide a more simplified design with less mechanical joints which may be less susceptible to failure in harsh environments.

Journal ArticleDOI
TL;DR: In this paper, a recursive system identification and retuning methodology is presented for a recently developed delayed feedback vibration absorber, which is performed to maintain optimal vibration suppression properties for wideband excitations.
Abstract: A recursive system identification and retuning methodology is presented for a recently developed delayed feedback vibration absorber. The retuning is needed against the parametric variations in the system. It is performed to maintain optimal vibration suppression properties for wideband excitations. The optimized absorber offers minimum peak frequency response within the given wideband frequency range. A new scheme is introduced for the tuning of the absorber as the system experiences structural variations. The scheme suggests a nested procedure of two optimization steps, one for identification and the other for control. Feasibility of the proposed methodology is demonstrated through simulations. One of the examples deals with a single-degree-of-freedom system, and the second one is for a two-degree-of-freedom setting. Results show that with only three iterations used for the first example and five iterations used for the second example in the parameter identification part of the process, the frequency response peaks are reduced by 25%.

Journal ArticleDOI
TL;DR: In this paper, a dynamic absorber is added to an externally excited pendulum, which can move in the transverse or longitudinal direction, and the quenching efficiency of the two different systems is compared.

Proceedings ArticleDOI
19 Jun 2000
TL;DR: In this article, a control law to achieve phase tracking by controlling the heating of the SMA elements is developed and implemented, and the results demonstrate that substantial improvements in vibration attenuation can be achieved through the implementation of SMA ATVA.
Abstract: Controlled continuous tuning of the stiffness of shape memory alloy (SMA) spring elements of an adaptively tunable vibration absorber (ATVA) is a novel concept for adaptive-passive vibration control. Minimization of the vibration of a primary system is achieved indirectly via stiffness control of the SMA structural elements supporting a secondary mass. Stiffness control is further achieved via the heating of the SMA elements. In this paper a control law to achieve phase- tracking by controlling the heating of the SMA elements is developed and implemented. Successful analytical and experimental results demonstrate the feasibility of continuous control of the SMA ATVA. Performance of the SMA ATVA is compared to the performance of comparable passive tuned vibration absorbers (TVA). The comparison shows that substantial improvements in vibration attenuation can be achieved through the implementation of the SMA ATVA.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Journal Article
TL;DR: In this article, the theory, experiments and practical application of ball vibration absorber for horizontal movement are described, as well as its efficiency in comparison with that of the pendulum absorber.
Abstract: In this paper the theory, experiments and practical application of ball vibration absorber for horizontal movement are described, as well as its efficiency in comparison with that of the pendulum absorber. Two prototypes of such absorbers were recently realized on small TV towers in the Czech Republic and their dynamic behaviour started to be examinated.

Journal ArticleDOI
TL;DR: In this paper, a thin, elastic cylindrical shell is adopted as a simple model of the fuselage and several dynamic absorbers are attached to the shell for vibration and noise control.

Patent
27 Jan 2000
TL;DR: In this paper, a vibrational damping means is used to reduce or eliminate the vibrations of the stylus of a measuring probe mounted on a machine, and which are transmitted to the probe stylus via the machine quill and probe body.
Abstract: Vibrations of the stylus (4) of a measuring probe (1) mounted on a machine, and which are transmitted to the probe stylus via the machine quill and probe body, are reduced or eliminated by a vibration damping means positioned within a cavity of the stylus. FIG. 2 illustrates a first embodiment in which the vibration damping means is a unconstrained rubber cylinder (16), in a hollow cartridge (12) connected to the stylus at its tip. Alternatively a dynamic vibration absorber can be used.

Journal ArticleDOI
TL;DR: In this article, two passive techniques for vibration reduction in mechanical systems: the first one is based on dynamic vibration absorbers (DVAs) and the second uses resonant circuit shunted (RCS) piezoceramics.
Abstract: This paper examines two passive techniques for vibration reduction in mechanical systems: the first one is based on dynamic vibration absorbers (DVAs) and the second uses resonant circuit shunted (RCS) piezoceramics. Genetic algorithms are used to determine the optimal design parameters with respect to performance indexes, which are associated with the dynamical behavior of the system over selected frequency bands. The calculation of the frequency response functions (FRFs) of the composite structure (primary system + DVAs) is performed through a substructure coupling technique. A modal technique is used to determine the frequency response function of the structure containing shunted piezoceramics which are bonded to the primary structure. The use of both techniques simultaneously on the same structure is investigated. The methodology developed is illustrated by numerical applications in which the primary structure is represented by simple Euler-Bernoulli beams. However, the design aspects of vibration control devices presented in this paper can be extended to more complex structures.

Journal ArticleDOI
TL;DR: In this article, a method is developed to predict the stationary random response of a beam which has been modified by the attachment of a damped, lumped assembly of linear mechanical elements.

Journal Article
TL;DR: In this paper, an investigation is carried out with an actual 13-story building to assess the viability and effectiveness of a recently proposed roof isolation system that aims at reducing the response of buildings to earthquakes.
Abstract: An investigation is carried out with an actual 13-story building to assess the viability and effectiveness of a recently proposed roof isolation system that aims at reducing the response of buildings to earthquakes. The roof isolation system entails the insertion of flexible laminated rubber bearings between a building's roof and the columns that support it, and the addition of viscous dampers connected between the roof and the rest of the building. It is based on the concept of a vibration absorber and on the idea of making the roof, flexible bearings, and viscous dampers respectively constitute the mass, spring, and dashpot of such an absorber. The investigation includes a comparison of the building's response under a severe ground motion when it is considered with and without the isolation system, as well as the determination of the properties and size of the required isolation system components. It is found that the proposed isolation system is effective, is constructable, and has the potential to become an attractive way to reduce structural and nonstructural earthquake damage in low and medium-rise buildings.

Journal ArticleDOI
TL;DR: In this article, a hybrid dynamic vibration absorber (HDVA) is proposed to assign tunable zero and poles to a closed-loop primary system, subject to a modest constraint that the prototype is minimum-phase with relative degree 2.
Abstract: This paper presents a hybrid dynamic vibration absorber (HDVA) that is able to assign tunable zeros and poles to a closed-loop primary system. A detailed procedure is presented to design the HDVA and match closed-loop response of a primary system to a prototype transfer function, subject to a modest constraint that the prototype is minimum-phase with relative degree 2.

Journal ArticleDOI
TL;DR: In this paper, discrete domain analysis is presented and it is shown that discrete domain control design for DR yields better vibration suppression considering the sampled control structure in implementations.
Abstract: The delayed resonator (DR) is a new active vibration absorption technique that uses time-delayed partial state feedback to generate ideal resonance on a passive vibration absorber. It has many attractive features such as real-time tunability, ease of implementation, and total suppression of vibration for tonal frequency disturbances. The DR controller has been developed in continuous domain until now. In this paper, discrete domain analysis is presented. Simulation results indicate an expected dependency of stability on the sampling period for this active control strategy. A major advantage of discrete domain analysis is the reduction of characteristic roots from infinite to finite numbers and consequent simplicity in the analysis and design of the controller. It is shown that discrete domain control design for DR yields better vibration suppression considering the sampled control structure in implementations.

Journal ArticleDOI
TL;DR: In this paper, a pendulum-type passive vibration absorber attached to a primary structure whose orientation varies is evaluated and factors that affect the performance of the absorber are highlighted.

Proceedings ArticleDOI
01 Jan 2000
TL;DR: In this paper, a nonlinear robust control scheme based on a variable structure is designed and simulated for vibration absorber design and a robust synthesis of the discontinuity surface based on classical frequency loop-shaping and the edge theorem is discussed.
Abstract: A new, simple control method for vibration absorber design is presented. A nonlinear robust control scheme based on a variable structure is designed and simulated. Robust synthesis of the discontinuity surface based on classical frequency loop-shaping and the edge theorem is discussed. The proposed control scheme has two advantages over the current existing vibration absorber design methodologies: 1) it is completely insensitive to changes in the stiffness and damping of the absorber, and strongly robust against parametric uncertainties of the primary vibrating structure; and 2) it is capable of suppressing both cyclic and random vibrations over a very wide range of frequencies.

Journal ArticleDOI
TL;DR: In this paper, a smart structure using piezoelectric devices electrically shunted by an inductor-resistor circuit was tested for passive microvibration control of an aluminum beam of a 1010×60×30Tmm size simply supported at both ends.
Abstract: A smart structure using piezoelectric devices electrically shunted by an inductor-resistor circuit was tested for passive microvibration control of an aluminum beam of a 1010×60×30Tmm size simply supported at both ends. The piezoelectric devices were attached to the beam on the top and bottom surfaces at the middle point of it. It is known that such devices with a shunted circuit work like a dynamic vibration absorber. For the piezoelectric devices, 8d33 stack type devices of a 10×10×20Hmm size, and 2d31 type devices of a 60×60×5T mm size were tested, showing almost the same performance. Through the tests, it was confirmed that the smart structure could effectively suppress microvibration of the beam in a high frequency, and the smart structure could be applied to microvibration control of precision equipment.

Journal ArticleDOI
TL;DR: In this paper, a design method for vibration control of a structure with an active dynamic vibration absorber involving actuator constraints is proposed, taking into account both the maximum control input and the maximum stroke of the actuator by using a nonlinear function of hyperbolic tangent.
Abstract: This paper proposes a design method for vibration control of a structure with an active dynamic vibration absorber involving actuator constraints. We formulate the linear parameter varying system taking into account both the maximum control input and the maximum stroke of the actuator by using a nonlinear function of hyperbolic tangent. The gain-scheduled control based on the linear matrix inequality is obtained so that the closed-loop system is stable and has good performance even if saturation phenomena of the actuator occur. By simulations we verify that the proposed method is useful for not only an impulsive input but also a non-stationary random input such as earthquakes.

Proceedings ArticleDOI
06 Mar 2000
TL;DR: In this paper, the authors proposed a comfort evaluation prediction system (CEPS) that can predict subjective evaluation from floor vibration, considering passengers' constitutions and wheelchair types, using a modal experiment.
Abstract: Against discomfort of vehicles for wheelchair users, countermeasures such as a vibration absorber are required. To determine the optimal characteristics of the absorber, the authors had proposed the Comfort Evaluation Prediction System (CEPS) that can predict subjective evaluation from floor vibration, considering passengers' constitutions and wheelchair types. The purpose of this paper is to construct a model that simulates the vibration transmitted to the passenger as part of the CEPS. The authors modeled a wheelchair-bound passenger and estimated unknown parameters by the result of a modal experiment. Then, some simulations were carried out to suggest the applicability of the model. (A) For the covering abstract of the conference see ITRD E206480.