• Title/Summary/Keyword: Motion-induced Stiffness Variation

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Modeling and Verification for Stability Analysis of Axially Oscillating Cantilever Beams (축 방향 왕복운동을 하는 외팔보의 안정성 해석을 위한 모델링 및 검증)

  • Kim, Sung-Do;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.2 s.107
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    • pp.176-182
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    • 2006
  • Modeling and verification for stability analysis of axially oscillating cantilever beams are investigated in this paper Equations of motion for the axially oscillating beams are derived and transformed into dimensionless forms. The equations include harmonically oscillating parameters which are related to the motion-induced stiffness variation. stability diagram is obtained by using the multiple scale perturbation method. To verify the accuracy of the modeling method, several points in the plane of the stability diagram are presented and solved. The present modeling method proves to be as accurate as a nonlinear finite element modeling method.

Modeling and Verification for Stability Analysis of Axially Oscillating Cantilever Beams (축 방향 왕복운동을 하는 외팔보의 안정성 해석을 위한 모델링 및 검증)

  • Kim, Sung-Do;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.708-713
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    • 2005
  • Modeling and verification for stability analysis of axially oscillating cantilever beams are investigated in this paper. Equations of motion for the axially oscillating beams are derived and transformed into dimensionless forms. The equations include harmonically oscillating parameters which are related to the motion-induced stiffness variation. Stability diagram is obtained by using the multiple scale perturbation method. To verify the accuracy of the modeling method, several points in the plane of the stability diagram are presented and solved. The present modeling method proves to be as accurate as a nonlinear finite element modeling method.

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Dynamic Analysis of Cantilever Plates Undergoing Translationally Oscillating Motion (면내 방향 맥동 운동하는 외팔평판의 동적 안정성 해석)

  • Hyun, Sang-Hak;Yoo, Hong-Hee
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.366-371
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    • 2001
  • Dynamic stability of an oscillating cantilever plate is investigated in this paper. The equations of motion include harmonically oscillating parameters which originate from the motion-induced stiffness variation. Using the multiple scale perturbation method is employed to obtain a stability diagram. The tability diagram shows that relatively large unstable regions exist when the frequency of oscillation is near twice the frequencies of the 1st torsion natural mode and the 1st chordwide bending mode.

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Analysis of Particle Collision on a Rotating Cantilever Beam Having a Concentrated Mass (집중 질량을 가진 회전하는 외팔 보의 질점 충돌 해석)

  • Lim, Hong-Seok;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.714-714
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    • 2005
  • This paper presents the modeling and impact analysis for a rotating cantilever beam having a concentrated mass. The concentrated mass takes an impact force during the rotating motion and the transient response of the beam induced by the impact is calculated by applying the Rayleigh-Ritz assumed mode method. The stiffness variation effect caused by the rotating motion is considered in this modeling. The effects of the concentrated mass size, impact position and the angular velocity of the beam on the transient responses are investigated through numerical studies.

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Vibration Analysis of Rotating Cantilever Plates with Arbitrary Orientation Angle (임의의 자세를 갖는 외팔평판의 진동해석)

  • Kim, Sung-Kyun;Yoo, Hong-Hee
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.8
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    • pp.1331-1337
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    • 2003
  • Linearized equations of motion for the vibration analysis of rotating cantilever plates with arbitrary orientation angle are derived in the present work. Two in-plane stretch variables are introduced to be approximated. The use of the two in-plane stretch variables enables one to derive the equations of motion which include proper motion-induced stiffness variation terms. The equations of motion are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of the dimensionless parameters on the modal characteristics of rotating cantilever plates are investigated through numerical study. The natural frequency loci veering along with the associated mode shape variations, which occur while the rotating speed increases, are also presented and discussed.

Dynamic stability analysis of axially oscillating cantilever beams (축방향 왕복운동을 하는 외팔보의 동적 안정성 해석)

  • 현상학;유홍희
    • Journal of KSNVE
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    • v.6 no.4
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    • pp.469-474
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    • 1996
  • Dynamic stability of an axially oscillating cantilever beam is investigated in this paper. The equations of motion are derived and transformed into non-dimensional ones. The equations include harmonically oscillating parameters which originate from the motion-induced stiffness variation. Using the equations, the multiple scale perturbation method is employed to obtain a stability diagram. The stability diagram shows that relatively large unstable regions exist around the frequencies of the first bending natural frequency, twice the first bending natural frequency, and twice the second bending natural frequency. The validity of the diagram is proved by direct numerical simulations of the dynamic system.

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Dynamic Analysis of a Rotating Blade Considering the Fluid Induced Exteral Force (유체유동에 의한 외력을 고려한 회전 블레이드의 동역학적 거동해석)

  • Seo, Seok;Yu, Hong-Hui;Yun, Jun-Yong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2259-2265
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    • 2000
  • A dynamic modeling of a rotating pretwist blade which interacts with the fluid is proposed in this study. The hybrid deformation variable modeling method is employed to derive the equations of motion. The external force and moment induced by the fluid (with fixed configurations of the blade) are obtained by fluid flow analysis and tabulated in a database. This database is efficiently utilized to save the computational effort to calculate the dynamic response of the blade. The numerical results show that the fluid affects the transient response as well as frequency characteristics of the system.

Dynamic Analysis of a Cantilever Beam Undertaking Impulsive Force That Undergoes Rigid Body Motion (강체 운동을 고려한 충격을 받는 외팔 보의 동적 해석)

  • Lim, Hong-Seok;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.890-895
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    • 2005
  • This paper presents the dynamic analysis of a cantilever beam undertaking impulsive force that undergoes rigid body motion. The transient response of the beam induced by the impulsive force and the rigid body motion is calculated based on hybrid deformation variable modeling method by applying the Rayleigh-Ritz assumed mode method. The stiffness variation effect caused by the rigid body motion is considered in this modeling. The effects of the impulsive force position and the angular velocity on the transient responses of the beam are investigated through numerical studies.

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Dynamic Analysis of an Impulsively Forced Rotating Cantilever Beam (충격력을 받는 회전하는 외팔 보의 동적 해석)

  • Lim, Hong-Seok;Yoo, Hong-Hee
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.16 no.3 s.108
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    • pp.226-232
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    • 2006
  • This paper presents the dynamic analysis of an impulsively forced rotating cantilever beam with rigid body motion. The transient response induced by the impulsive force and the rigid body motion of the beam are calculated using hybrid deformation variable modeling with the Rayleigh-Ritz assumed mode methods. The stiffness variation effect due to the rigid body motion of the beam is considered in this study Also, the effects of the impulsive force position and the angular velocity on the transient responses of the beam are investigated through numerical works.

Dynamic Stability Analysis of Axially Oscillating Cantilever Beams with a Concentrated Mass (축방향 왕복운동을 하는 집중질량을 가진 외팔보의 동적 안정성 해석)

  • Hyun, Sang-Hak;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.718-723
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    • 2000
  • Dynamic stability of an axially oscillating cantilever beam with a concentrated mass is investigated in this paper. The equations of motion are derived and the derived equations include harmonically oscillating parameters which originate from the motion-induced stiffness variation. Under certain conditions of the frequency and the amplitude of oscillating motion, parametric instabilities may occur. The multiple scale perturbation method is employed to obtain the stability analysis results. It is found that the system stability varies with the magnitude or the location of the concentrated mass. Instability increases as the concentrated mass approaches to the free-end or its magnitude increases.

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