• Title/Summary/Keyword: Flexible dynamics

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Tumbling Dynamics of Rod-like and Semi-flexible Polymers in Simple Shear and Mixed Flows

  • Lee, Joo-Sung;Kim, Ju-Min
    • Macromolecular Research
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    • v.17 no.10
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    • pp.807-812
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    • 2009
  • In this work, we focus on the tumbling dynamics of rod-like and semi-flexible polymers in mixed flows, which vary from simple shear to pure rotation. By employing a bead-rod model, the tumbling pathways and periods are examined with a focus on the angular distribution of their orientation. Under the mixed flows, the tumbling dynamics agreed well with earlier studies and confirmed the predicted scaling laws. We found that the angular distribution deviates from that of shear flow as the flow type approaches pure rotation. Finally, we investigated the angular distribution of $\lambda$-DNA in a shear flow and found that the present numerical simulations were in quantitative agreement with the previous experimental data.

A Study of Vibration Control of a Slender Structure Using a Multi-Degree-of-Freedom Manipulator (다 자유도 운동장치를 이용한 세장구조물의 진동제어 연구)

  • Kim, Nak-In;Lee, Jong-Won
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1227-1234
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    • 2001
  • A multi d.o.f robotic manipulator is considered for multi-axis vibration control of a slender structure, using the concept of the flow source based vibration control. In order not to cause the motion saturation of the manipulator system, a hybrid dynamics associated with the flexible and desired manipulator error dynamics is also modeled as the control object. It is numerically shown that the flexible vibrations and the base motions of a test structure can be effectively controlled with the proposed hybrid dynamics.

Modeling of the Maglev Vehicle Running over the Elevated Guideway Using Flexible Multibody Dynamics (유연다물체 동역학을 이용한 자기부상열차 동역학 모델링 연구)

  • Lee, Jong-Min;Kim, Young-Joong;Kim, Kuk-Jin;Kim, Dong-Sung;Kim, Sook-Hee;Han, Hyung-Suk
    • Journal of the Korean Society for Railway
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    • v.9 no.6 s.37
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    • pp.792-797
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    • 2006
  • In general, the Maglev vehicle is ran over the elevated guideway consisted of steel or concrete structure. Since the running behaviour of the vehicle is affected by the flexibility of the guideway, the consideration of the flexibility of guideway is needed for evaluation of dynamics of both the vehicle and guideway. A new technique based on flexible multibody dynamics is proposed to model the Maglev vehicle, levitation controller, and guideway into a coupled model. To verify the technique, an urban Maglev vehicle is analyzed using the technique and discussions are carried out.

Multi-flexible Body Dynamic Analysis of a Heavy Trailer Vehicle Passing a Bump (대형 트레일러 차량의 범프 통과 시 유연다물체 동역학 해석)

  • Kim, J.Y.;Kim, H.S.;Kim, J.G.
    • Journal of Power System Engineering
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    • v.13 no.5
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    • pp.40-45
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    • 2009
  • This article deals with the transient analysis using multi-flexible body dynamics of a trailer vehicle, which is passing a bump on the flat road. In order to investigate the transient dynamic behavior of the trailer, we developed an equivalent finite element model for the trailer and a vehicle dynamic model for the truck using multi-body dynamics. The driving condition considered here is set as the trailer vehicle passes a bump on the flat road in 7km/h. And we investigate the time histories of vertical load and deflections on connecting points between the trailer and truck during the vehicle passes a bump. Due to the dynamic load resulted from the driving condition, additional stress concentrations are found in the trailer and the suspension connecting points between the trailer and rear axles along with kingpin.

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Analysis of Dynamic Response of a Floating Crane and a Cargo with Elastic Booms Based on Flexible Multibody System Dynamics (붐의 탄성효과를 고려한 해상크레인의 유연 다물체 동역학 해석)

  • Park, Kwang-Phil;Cha, Ju-Hwan;Lee, Kyu-Yeul
    • Journal of the Society of Naval Architects of Korea
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    • v.47 no.1
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    • pp.47-57
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    • 2010
  • This study analyzes the dynamic response of a floating crane with a cargo considering an elastic boom to evaluate(or for evaluation of) its flexibility effect on their dynamic response. Flexible multibody system dynamics is applied in order to establish a dynamic equation of motion of the multibody system, which consists of flexible and rigid bodies. In addition, a floating reference frame and nodal coordinates are used to model the boom as a flexible body. The study also simulates the coupled surge, pitch, and heave motions of the floating crane carrying the cargo with three degrees of freedom by numerically solving the equation. Finally, the simulation results of the elastic and rigid booms are comparatively analyzed and the effects of the flexible boom are discussed.

Modeling of flexible stick balencer and controller design (Flexible stick balencer에 대한 modeling과 제어에 관한 연구)

  • Seo, Ki-Won;Cho, Hwang
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.233-236
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    • 1996
  • This paper describes a liner state-space model for a flexible stick balencer. The method employed to generate the model utilizes a separable formulation of assumed modes to represents the transverse displacement due to bending Lagrangian dynamics are applied to determine the kinetic and potential energies for the system. The resultant dynamic equations are then organized into a state space model and linearized using Taylor series expansion method. A minimum order observer is designed to estimate unmeasurable states.

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Recent Trends in Multibody Dynamics Researches reviewed from the papers presented in the Multibody2003 and in the 2003 ASME DETC (Multibody2003와 2003 ASME DETC의 논문들을 통해본 다물체동역학 연구의 세계적 연구추세)

  • Yoo, Wan-Suk
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1714-1717
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    • 2003
  • ECCOMAS Thematic Conference Multibody 2003 was held at IST (Instituto Superior Technico), Lisbon, Portugal from July 1 to July 4. 2003. And MBDV(Multibody Dynamics and Vibration) in the 2003 ASME DETC was held at Chicago, U.S.A. from September 2 to September 6. In this paper, the presented papers in these conferences were reviewed and the trends in the multibody dynamics are summarized. The session titles in these conferences include Flexible Multibody Dynamics, Vehicle Dynamics, Contact, Biomechanics, Real-time Challenges, Spatial manipulator and Control, Multidisciplinary Applications, and Advanced Education. The poster session was also organized for more discussions in the Multibody2003 conference.

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