Showing papers on "Dynamic Vibration Absorber published in 2015"
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TL;DR: In this paper, an inerter-based dynamic vibration absorber (IDVAs) was proposed to improve the performance of the H∞ and H2 optimization problem.
190 citations
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TL;DR: In this paper, a nonlinear tuned vibration absorber (NLTVA) is proposed to mitigate the nonlinear resonance of a mechanical system, which is tailored according to the non-linear restoring force of the primary system.
128 citations
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TL;DR: In this paper, an acoustic multi-stopband metamaterial plate is designed by integrating two-degree of freedom (DOF) mass-spring subsystems with an isotropic plate to act as vibration absorbers.
122 citations
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TL;DR: Simulation results prove the effectiveness of the proposed finite-frequency H ∞ controller method and show that the human body is much sensitive to vibrations between 4 and 8 Hz.
Abstract: In this paper, the parameter optimization and H ∞ control problem of active suspensions equipped in in-wheel motor driven electric ground vehicles are investigated. In order to better isolate the force transmitted to motor bearing, dynamic vibration absorber (DVA) is installed in the active suspension. Parameters of the vibration isolation modules are also optimized in order to achieve better suspension performances. As the human body is much sensitive to vibrations between 4 and 8 Hz, a finite-frequency state-feedback H ∞ controller is designed to achieve the targeted disturbance attenuation in the concerned frequency range while other performances such as road holding capability and small suspension deflection are also maintained. The performance of the proposed finite-frequency H ∞ controller is compared with that of an entire frequency one, simulation results prove the effectiveness of the proposed control method.
100 citations
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TL;DR: In this paper, an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor, where the motor shaft moves, a difference of voltage is generated across the transducers coil.
Abstract: This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force proportional to current following the Lorentz principle if the circuit is closed around the transducer coil. If an electronic circuit consisting of a capacitor, an inductance and a resistance with the appropriate configuration is connected, the resulting force reflected back into the mechanical domain is equivalent to that achieved by a mechanical inerter-based device. The proposed configuration is easy to implement and very versatile, provided a high quality conversion system with negligible losses. With the use of electromagnetic devices, a new generation of vibration absorbers can be realized, for example in the electrical domain it would be relatively uncomplicated to synthesize multi-frequency or real time tunable vibration absorbers by adding electrical components in parallel. In addition by using resistance emulators in the electrical circuits, part of the absorbed vibration energy can be converted into usable power. Here an electromagnetic tuned inerter damper (E-TID) is tested experimentally using real time dynamic substructuring. A voltage compensation unit was developed in order to compensate for coil losses. This voltage compensation unit requires power, which is acquired through harvesting from the vibration energy using a resistance emulator. A power balance analysis was developed in order to ensure the device can be self sufficient. Promising experimental results, using this approach, have been obtained and are presented in this paper. The ultimate goal of this research is the development of autonomous electromagnetic vibration absorbers, able to harvest energy, convert it into usable power, and use it for vibration control and health monitoring.
99 citations
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TL;DR: In this article, an adaptive tuned vibration absorber (ATVA) incorporating multilayer magnetorheological elastomers (MREs) was designed and prototyped, and its performance under various scan frequencies was tested on a horizontal vibration platform.
Abstract: Adaptive tuned vibration absorbers (ATVAs) featuring magnetorheological elastomers (MREs) have attracted considerable research interests because of the advantages of fast response, controllable frequency, and broad working range. Generally, the ATVA uses single layer of MRE sheet, which has some issues such as small oscillator stroke and being effective only on high frequency. In this research, an ATVA which incorporates multilayer MRE sheets was designed and prototyped. Its performance under various scan frequencies was tested on a horizontal vibration platform. A theoretical model was proposed to predict the MRE absorber performance. For the clear demonstration of the advantages of multilayered MRE absorber, two kinds of absorbers with only one layer of MRE were prepared as comparison. The experiments compared the vertical support capability and the tuning frequency range of these two ATVAs, which have clearly highlighted the capabilities of multilayered MRE absorber with larger oscillator stroke (as large as 13.6 mm) and lower working frequencies (as low as 3.2 Hz). The vibration absorption evaluation was conducted by mounting the multilayered MRE absorber on a single-degree-of-freedom system. The results identify that the ATVA with multilayered MREs could work lower than 10 Hz, which is very difficult for the one with single layer MRE. Additionally, the performance of the passive and adaptive tuned laminated MRE absorbers on attenuating a swept frequency vibration are presented, respectively. The ATVA was more effective than the passive absorber over a wide frequency range.
92 citations
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TL;DR: The sensitivity of these boundaries to uncertainty in the nonlinear tuned vibration absorber (NLTVA) parameters is also investigated in this paper, where the combination of numerical continuation of periodic solutions, bifurcation detection and tracking, and global analysis is used to identify boundaries in the NLTVA parameter space delimiting safe, unsafe and unacceptable operations.
84 citations
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TL;DR: In this paper, the authors proposed a novel compact shock absorber with both damping and stiffness variable characteristics, which is developed based on MR fluid through an innovative design and a prototype is tested by MTS to characterize the variable damping properties.
Abstract: A shock absorber is an important device for vehicle suspension. The semi-active suspension requires the damping or stiffness of the shock absorber to be controllable. This paper proposed a novel compact shock absorber with both damping and stiffness variable characteristics. The shock absorber is developed based on MR fluid through an innovative design. A prototype is tested by MTS to characterize the variable damping and stiffness properties. A mathematical model that incorporated the Bingham model is established and an optimization method is adopted to identify the parameters. The coherence of experiments and the proposed model verified the control ability of dual damping and stiffness of the shock absorber.
83 citations
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TL;DR: In this article, the effect of the DVAs on the vibration absorption of the FST subjected to vehicle dynamic loads is evaluated with the help of the insertion loss in one-third octave frequency bands.
Abstract: This study aims to effectively and robustly suppress the low-frequency vibrations of floating slab tracks (FSTs) using dynamic vibration absorbers (DVAs). First, the optimal locations where the DVAs are attached are determined by modal analysis with a finite element model of the FST. Further, by identifying the equivalent mass of the concerned modes, the optimal stiffness and damping coefficient of each DVA are obtained to minimise the resonant vibration amplitudes based on fixed-point theory. Finally, a three-dimensional coupled dynamic model of a metro vehicle and the FST with the DVAs is developed based on the nonlinear Hertzian contact theory and the modified Kalker linear creep theory. The track irregularities are included and generated by means of a time–frequency transformation technique. The effect of the DVAs on the vibration absorption of the FST subjected to the vehicle dynamic loads is evaluated with the help of the insertion loss in one-third octave frequency bands. The sensitivities of the m...
53 citations
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TL;DR: In this article, the performance of nonlinear absorbers in vibration attenuation of non-linear primary oscillators was investigated to obtain time-averaged power flow variables, as well as kinetic energies.
Abstract: The vibrational power flow characteristics of a two-degree-of-freedom system are investigated to examine the performance of nonlinear absorbers in vibration attenuation of nonlinear primary oscillators. The nonlinearities in the oscillator and those in the absorber are both characterised by cubic restoring and damping forces. Both analytical approximations and numerical integrations are used to obtain time-averaged power flow variables, as well as kinetic energies of the system. Power absorption ratio and the kinetic energy of the nonlinear oscillator are proposed to quantitatively evaluate the effectiveness of nonlinear absorbers with respect to the existing nonlinearities in the oscillator. Comparing with linear absorbers, it is found that softening (hardening) stiffness absorber provides benefits for vibration mitigation of a hardening (softening) stiffness primary oscillator by enhancing power absorption efficiency and reducing the kinetic energy of the oscillator so that the functioning frequency range of the absorber can be enlarged. Nonlinear cubic damping in the absorber is shown beneficial for vibration suppression as the power absorption ratio becomes large at resonance frequencies so that the peak power flow and kinetic energy levels are reduced. The developed model can be conveniently extended to study other types of nonlinearities in the absorber/oscillator. Conclusions and suggestions are provided for applications.
49 citations
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TL;DR: In this paper, the authors considered the design of a compact isolator with quasi-zero stiffness, which has high vibration control properties at low weight and dimensions and can protect against low-frequency vibration.
Abstract: This article considers the design of a compact isolator with quasi-zero stiffness. It has high vibration control properties at low weight and dimensions. Also the developed vibration isolator with quasi-zero stiffness can protect against low-frequency vibration. The vibration isolator is of a passive type, made from a single elastic material, which will be compact and convenient in manufacturing. An analytical study of the vibration isolation, its manufacturing and experimental static study are presented. The natural frequency of the developed vibration isolator with quasi-zero stiffness is less than 1 Hz.
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TL;DR: In this paper, a dynamic vibration absorber (DVA) is used as an effective vibration control device, which is essentially a secondary mass, attached to an original system via a spring and damper.
Abstract: A dynamic vibration absorber (DVA) can be used as an effective vibration control device. It is essentially a secondary mass, attached to an original system via a spring and damper. The natural freq...
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TL;DR: In this paper, the authors present an approach for detuning a recently developed general tautochronic absorber design without bifilar suspensions, which makes it possible to consider a wide class of tautochecronic absorbers, e.g. absorbers with amplitude-independent frequency.
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TL;DR: The objective of this study is to mitigate, or even completely eliminate, the limit cycle oscillations in mechanical systems using a passive nonlinear absorber, termed the nonlinear tuned vibration absorber (NLTVA).
Abstract: The objective of this study is to mitigate, or even completely eliminate, the limit cycle oscillations in mechanical systems using a passive nonlinear absorber, termed the nonlinear tuned vibration absorber (NLTVA). An unconventional aspect of the NLTVA is that the mathematical form of its restoring force is not imposed a priori, as it is the case for most existing nonlinear absorbers. The NLTVA parameters are determined analytically using stability and bifurcation analyses, and the resulting design is validated using numerical continuation. The proposed developments are illustrated using a Van der Pol–Duffing primary system.
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TL;DR: A new method is presented that determines the non-linear behavior of the barrel with a passive vibration absorber and optimizes the absorber using the genetic algorithm (GA) and combined with the classical finite element method.
Abstract: We developed a new finite element formula for the barrel-projectile interaction.Then vertical tip displacement of the barrel was determined using Newmark's algorithm.We designed and optimized a passive vibration absorber to reduce the tip deflection of the barrel.For the optimization, we developed a new approach that combines the FEM and GA. The non-linear vibrations of a barrel, induced by the interaction with a high-speed moving projectile, negatively affect the shooting accuracy of a weapon. This study presents a new method that determines the non-linear behavior of the barrel with a passive vibration absorber and optimizes the absorber using the genetic algorithm (GA). Since both the barrel geometry and its coupling with the absorber are non-linear, a new finite element method (FEM) approximation has been developed for the interaction of barrel and projectile and combined with the classical finite element method. The final coupled equation of motion of entire system has been solved by a step by step integration, and for minimum tip deflection of the barrel, a GA has been then used in order to optimize the some parameters of the absorber. The results of analyses of the proposed FEM model were compared, and a good agreement was seen with the existing literature. In another example, the FEM-GA integrated optimization procedure was also used for the optimization of a passive vibration absorber, and a more accurate result (0.5% better) was obtained when compared to the experimental study given in literature.
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TL;DR: In this article, the combined control and energy harvesting characteristics of an autoparametric vibration absorber consisting of a base structure subjected to the external force and a cantilever beam with a tip mass are investigated.
Abstract: The combined control and energy harvesting characteristics of an autoparametric vibration absorber consisting of a base structure subjected to the external force and a cantilever beam with a tip mass are investigated. The piezoelectric sheets are attached to the cantilever beam to convert the vibrations of the base structure into electrical energy. The coupled nonlinear representative model is developed by using the extended Hamiton's principle. The effects of the electrical load resistance on the frequency and damping ratio of the cantilever beam are analyzed. The impacts of the external force and load resistance on the structural displacements of the base structure and the beam and on the level of harvested energy are determined. The results show that the initial conditions have a significant impact on the system's response. The relatively high level of energy harvesting is not necessarily accompanied with the minimum displacements of the base structure.
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TL;DR: In this article, self-sensing technology was introduced into an adaptive tuned vibration absorber, incorporating a laminated magnetorheological elastomer (MRE) structure, a hybrid magnetic system and a selfsensing component.
Abstract: In this paper, self-sensing technology was introduced into an adaptive tuned vibration absorber, incorporating a laminated magnetorheological elastomer (MRE) structure, a hybrid magnetic system and a self-sensing component. The adoption of the laminated MRE structure and the hybrid magnetic system enables the absorber to have higher lateral flexibility and a wider effective frequency range. The integration of the self-sensing capability allows the absorber to operate without sensors and, at the same time, greatly reduces costs, required space and maintenance. A series of experiments were conducted to measure the frequency shift property, to verify the self-sensing capability and to evaluate its effectiveness on vibration reduction. The experimental results show that the natural frequency of the proposed absorber can be changed to 4.8 Hz at –3 A and 11.3 Hz at 3 A from 8.5 Hz at 0 A, the frequency of the self-sensed voltage equals the excitation frequency and, more importantly, the vibration control effectiveness of the self-sensing MRE absorber is experimentally verified and it is more effective on vibration reduction than a passive absorber.
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TL;DR: In this article, a tunable vibration absorber (TVA) is designed to suppress regenerative chatter in milling of cantilever plates, and an optimal algorithm is developed based on mode summation approach.
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TL;DR: In this article, a nonlinear piezoelectric tuned vibration absorber (NPTVA) is proposed for the mitigation of nonlinear resonances of mechanical systems, where the nonlinear restoring force is designed according to a principle of similarity.
Abstract: This paper proposes a piezoelectric vibration absorber, termed the nonlinear piezoelectric tuned vibration absorber (NPTVA), for the mitigation of nonlinear resonances of mechanical systems. The new feature of the NPTVA is that its nonlinear restoring force is designed according to a principle of similarity, i.e., the NPTVA should be an electrical analog of the nonlinear host system. Analytical formulas for the NPTVA parameters are derived using the homotopy perturbation method. Doing so, a nonlinear generalization of Den Hartog's equal-peak tuning rule is developed for piezoelectric vibration absorbers.
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TL;DR: In this article, the design and numerical simulation of a linear generator for use in an automobile shock absorber are presented, which employs high-performance rare earth permanent magnets with compact size to ensure efficient energy recovery.
Abstract: The design and numerical simulation of a linear generator for use in an automobile shock absorber are presented in this paper. The conceived linear generator employs high-performance rare earth permanent magnets with compact size to ensure efficient energy recovery. Finite element analysis and Matlab simulation are utilized to derive the generator configurations for the satisfactory utilization of magnets and optimized functioning. Experimentation was performed on a linear generator prototype and electromagnetic shock absorber to validate the numerical analysis. The numerical model is then utilized in the design of a full-scale energy-harvesting shock absorber with fluid damping and a linear generator. A novel feature of the presented work is the use of fluid amplification to simultaneously achieve energy dissipation and velocity amplification. Fluid amplification does not affect the dynamics of the system and increases the coil velocity by approximately eight times. Smooth variation in damping force, improved fail-safe characteristics, and absence of transmission elements, such as mechanical gears, are additional advantages of the system. Matlab Simscape evaluation is employed to analyze comfort, safety, and energy-harvesting characteristics, which are then compared with that of the conventional fluid shock absorber. Simulation with actual road excitation data indicates that the presented system harvests 15 W of the average power from each wheel. Lastly, the layout for integrating the presented shock absorber in McPherson suspension is discussed.
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TL;DR: In this article, a two-terminal mass (TTM) based vibration absorber with variable moment of inertia (VMI) is proposed for passive vehicle suspension, which is achieved by the motion of sliders embedded in a hydraulic driven flywheel.
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TL;DR: In this paper, a nonlinear energy dissipation associated with damping screens and the nonlinear coupling among sloshing modes has been considered for multiple tuned liquid damper (MTLD) systems.
Abstract: In traditional tuned liquid damper (TLD) installations, TLD tank(s) are tuned to a single optimal frequency as determined by well-known dynamic vibration absorber theory. A multiple tuned liquid damper (MTLD) is created when the sloshing frequencies are distributed over a range near the structural frequency. In this paper, an equivalent mechanical model for a structure–MTLD system is developed. A third-order nonlinear multimodal model is employed to assess nonlinear fluid affects and serve as independent model verification. To the authors’ knowledge, this is the first time the nonlinear energy dissipation associated with damping screens and the nonlinear coupling amongst sloshing modes has been considered for MTLD systems. MTLD systems consisting of one (traditional TLD), two, and three tanks are used to reduce the resonant response of a single degree of freedom structure. The MTLD provides structural control that is superior to a traditional TLD. The MTLD is less sensitive to the structural excit...
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TL;DR: In this article, an elastomer composite with controllable stiffness, known as a magnetorheological elastomers (MRE), is used in a dynamic vibration absorber whose natural frequency is tuned adaptively to the disturbance frequency through the application of an external magnetic field.
Abstract: An elastomer composite with controllable stiffness, known as a magnetorheological elastomer (MRE), is used in a dynamic vibration absorber whose natural frequency is tuned adaptively to the disturbance frequency through the application of an external magnetic field. The field-dependent property test of the fabricated MRE sample shows that the stiffness changes by more than six times compared to the baseline property value at a 40% iron powder volume concentration. The MRE is then used to fabricate a frequency-tunable dynamic absorber for mitigating transient vibrations of a one-degree-of-freedom system. Investigations show that the proposed absorber outperforms a conventional passive-type absorber throughout the tunable frequency range.
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TL;DR: In this article, a technique for optimizing the parameters of a vibration absorber in the presence of uncertain bounded structural parameters is presented. But it is not suitable for the RBO problem, especially when considering high levels of uncertainties.
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TL;DR: In this paper, a time-delayed acceleration feedback is introduced to convert a passive absorber into an active one, and the experimental results show that the proper choices of control parameters may broaden the effective frequency band of vibration absorption.
Abstract: The traditional passive absorber is fully effective within a narrow and certain frequency band. To solve this problem, a time-delayed acceleration feedback is introduced to convert a passive absorber into an active one. Both the inherent and the intentional time delays are included. The former mainly comes from signal acquiring and processing, computing, and applying the actuation force, and its value is fixed. The latter is introduced in the controller, and its value is actively adjustable. Firstly, the mechanical model is established and the frequency response equations are obtained. The regions of stability are delineated in the plane of control parameters. Secondly, the design scheme of control para- meters is performed to help select the values of the feedback gain and time delay. Thirdly, the experimental studies are conducted. Effects of both negative and positive feedback control are investigated. Experimental results show that the proper choices of control parameters may broaden the effective frequency band of vibration absorption. Moreover, the time-delayed absorber greatly suppresses the resonant response of the primary system when the passive absorber totally fails. The experimental results are in good agreement with the theoretical predictions and numerical simulations. A time-delayed acceleration feedback is introduced to convert a passive absorber into an active one. The design scheme of control parameters is performed for selection guidance of the values of feedback gain and time delay. Experimental results show the effectiveness of the time-delayed absorber on suppressing the vibration of the primary system.
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TL;DR: In this paper, a diversity-guided cyclic-network-topology-based constrained particle swarm optimization (Div-CNT-CPSO) algorithm was proposed to suppress high-amplitude vibrations of damped primary systems.
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TL;DR: In this article, the authors proposed a new compound MPP sound absorber architecture with excellent sound absorption performance both on higher sound absorption coefficient and broader absorption band compared with single MPP absorber.
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TL;DR: In this article, the authors derived a set of simple design formula of tuned vibration absorber with nonlinear viscous damping based on the frequency tuning for harmonic load for a damped structural system under white noise excitation.