• Title/Summary/Keyword: secondary beam

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Modeling and Vibration Feedback Control of Rotating Tapered Composite Thin-Walled Blade

  • Shim, Jae-Kyung;Sungsoo Na
    • Journal of Mechanical Science and Technology
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    • v.17 no.3
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    • pp.380-390
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    • 2003
  • This paper addresses the problem of the modeling and vibration control of tapered rotating blade modeled as thin-walled beams and incorporating damping capabilities. The blade model incorporates non-classical features such as anisotropy, transverse shear, secondary warping and includes the centrifugal and Coriolis force fields. For the rotating blade system, a thorough validation and assessment. of a number of non-classical features including the taper characteristics is accomplished. The damping capabilities are provided by a system of piezoactuators bonded or embedded into the structure and spread over the entire span of the beam. Based on the converse piezoelectric effect, the piezoactuators produce a localized strain field in response to a voltage and consequently, a change of the dynamic response characteristics is induced. A velocity feedback control law relating the piezoelectrically induced transversal bending moment at the beam tip with the appropriately selected kinematical response quantity is used and thebeneficial effects upon the closed-loop dynamic characteristics of the blade are highlighted.

Thermal Stability Analysis of 2-D Spacecraft Appendage (위성체 2-D 구조물의 열 안정성 해석)

  • 윤일성;송오섭;김규선
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.99-104
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    • 2001
  • Thermally induced vibration response of solar array is investigated. The solar array model consists of composite thin walled beam and solar blanket, spreader bar. The composite thin walled beam incorporates a number of nonclassical effects of transverse shear, primary and secondary warping, rotary inertia and anisotropy of constituent materials. The solar blanket is a membrane subjected to uniform tension in the z direction. The spreader bar is a rigid member. A coupled thermal structure analysis that includes the effects of structural deformations on heating and temperature gradient is investigated. A stability criterion given in parameters for establishes the conditions for thermal flutter.

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Three Dimensional Incompressible Unsteady Flows in a Circular Tube Using the Navier-Stokes Equations With Beam and Warming Method (원형관에서의 음해법을 이용한 차원 3차원 비압축성 부정류 흐름에 관한 수치모의)

  • Park, Ki-Doo;Lee, Kil-Seong;Sung, Jin-Young
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.1624-1629
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    • 2008
  • The governing equations in generalized curvilinear coordinates for a 3D pulsatile flow are the Incompressible Navier-Stokes (INS) equations with the artificial dissipative terms and continuity equation discretized using a second-order accurate, finite volume method on the nonstaggered computational grid. This method adopts a dual or pseudo time-stepping Artificial Compressibility (AC) method integrated in pseudo-time. The computational technique implements the implicit approximate factorization method of the Beam and Warming method (1978), which is the extension of the Alternate Direction Implicit (ADI) method. The algorithm yields practically identical velocity profiles and secondary flows that are in excellent overall agreement with an experimental measurement (Rindt & Steenhoven, 1991).

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Behaviors of CAD and CUS Thick-walled Composite I-Beam Under Torsional Load (비틀림 하중을 받는 두꺼운 복합재료 빔의 거동)

  • Park, Mi-Jung;Chun, Heoung-Jae;Byun, Jun-Hyung
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.202-206
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    • 2005
  • Most of studies on the open section composite beams are confined to the thin composite beams. There are some works focused on the thick composite beams but they are limited only to closed section beams. Therefore, it is required to develop an appropriate model to analyze the thick open section composite beams. In this study, the cantilever beams of two specific lay-up configurations are considered which are the circumferentially asymmetric stiffness (CAS) and circumferentially uniform stiffness (CUS) beams. Under the torsional loading, loading induced deformations are obtained for the thick beams using the suggested model. The model includes coupled stiffness and secondary warping effects. The results are compared with those obtained using thin beam model to observe the thickness effects. Those results are also compared with the finite element analysis results.

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