• Title/Summary/Keyword: Autoparametric Vibration Absorber

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Influence of Internal Resonance on Responses of an Autoparametric Vibration Absorber under Random Excitation (불규칙 가진력을 받는 동흡진기의 내부공진효과)

  • 조덕상;이원경
    • Journal of KSNVE
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    • v.10 no.6
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    • pp.1041-1047
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    • 2000
  • The main objectives of this study are to examine the random response of a vibration absorber system with autoparametric coupling in the neighborhood of internal resonance by Gaussian closure and to compare the results with those obtained by Monte Carlo simulation. The numerical simulation is found to support the main features of the nonlinear modal interaction in the neighborhood of internal resonance conditions. While the Gaussian closure exhibits regions of multiple solutions in the neighborhood of internal resonance, the numerical simulation gives only one solution depending on the assigned initial conditions. The on-off intermittency phenomena of the cantilever mode is observed in the Monte Carlo simulation over a small range of parameter.

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Modal Interactions in an Autoparametric Vibration Absorber to Narrow Band Random Excitation

  • Cho, Duk-Sang;Mo, Chang-Ki;Ban, Gab-Su;Lee, Kwang-Ho
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.97-104
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    • 2003
  • The main objectives of this study are to examine the random responses of a vibration absorber system with autoparametric coupling in the neighborhood of internal resonance subjected to narrow band random excitation by Gaussian closure scheme and to compare the results with those obtained by Monte Carlo simulation. The Monte Carlo simulation is found to support the main features of the nonlinear modal interaction in the neighborhood of internal resonance conditions. The jump phenomenon of the cantilever mode and saturation phenomenon of the main system are shown to occur if the excitation bandwidth is sufficiently small.

Stochastic Response of a System with Autoparametric Coupling (자기매계변수 연성을 갖는 응답의 통계적 특성)

  • 조덕상;김영종
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.4
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    • pp.387-394
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    • 2000
  • The nonlinear modal interaction of an autoparametric system under a broadband random excitation is investigated. The specific system examined is an autoparametric vibration absorber with internal resonance, which is typical of many common structural configurations. By means of Gaussian closure scheme the dynamic moment equations explaining the random responses of the system are reduced to a system of autonomous ordinary differential equations of the first and second moments. In view of equilibrium solutions of this system and their stability we examine the system responses. We could not find the destabilizing effect of damping, which was reported in References (18) and (20). The saturation phenomenon, which is well known in deterministic nonlinear system, did not take place lot this system subject to broadband random excitation.

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Control of chaotic dynamics by magnetorheological damping of a pendulum vibration absorber

  • Kecik, Krzysztof
    • Structural Engineering and Mechanics
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    • v.51 no.5
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    • pp.743-754
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    • 2014
  • Investigations of regular and chaotic vibrations of the autoparametric pendulum absorber suspended on a nonlinear coil spring and a magnetorheological damper are presented in the paper. Application of a semi-active damper allows controlling the dangerous motion without stooping of system and additionally gives new possibilities for designers. The investigations are curried out close to the main parametric resonance. Obtained numerical and experimental results show that the semi-active suspension may reduce dangerous motion and it also allows to maintain the pendulum at a given attractor or to jump to another one. Moreover, the results show that, for some parameters, MR damping may transit to chaotic motions.

Vibration mitigation of guyed masts via tuned pendulum dampers

  • Lacarbonara, Walter;Ballerini, Stefano
    • Structural Engineering and Mechanics
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    • v.32 no.4
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    • pp.517-529
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    • 2009
  • A passive vibration mitigation architecture is proposed to damp transverse vibrations of guyed masts. The scheme is based on a number of pendula attached to the mast and tuned to the vibration modes to be controlled. This scheme differs from the well-known autoparametric pendulum absorber system. The equations of motion of the guyed mast with an arbitrary number of pendula are obtained. The leading bending behaviour of a typical truss mast is described by an equivalent beam model whereas the guys are conveniently modeled as equivalent transverse springs whose stiffness comprises the elastic and geometric stiffness. By assuming a mast with an inertially and elastically isotropic cross-section, a planar model of the guyed mast is investigated. The linearization of the equations of motion of the mast subject to a harmonic distributed force leads to the transfer functions of the structure without the dampers and with the dampers. The transfer functions allow to investigate the mitigation effects of the pendula. By employing one pendulum only, tuned to the frequency of the lowest mode, the effectiveness of the passive vibration potential in reducing the motion and acceleration of the top section of the mast is demonstrated.