• 제목/요약/키워드: Coupling analysis

Search Result 2,272, Processing Time 0.042 seconds

Dynamic Analysis of Bending-Torsion Coupled Beam Structures Using Exact Dynamic Elements

  • Hong, Seong-Wook;Kang, Byung-Sik;Park, Joong-Youn
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.4 no.1
    • /
    • pp.15-22
    • /
    • 2003
  • Beams are often subject to bending-torsion coupled vibration due to mass coupling and/or stiffness coupling. This paper proposes a dynamic analysis method using the exact dynamic element for bending-torsion coupled vibration of general plane beam structures with joints. The exact dynamic element matrix for a bending-torsion coupled beam is derived, and the detailed procedure of using the exact dynamic element matrix is also presented. Three examples are provided for validating and illustrating the proposed method. The numerical study proves the proposed method to be useful for dynamic analysis of bending-torsion coupled beam structures with joints.

Dynamic Response Analysis of a Heavy Duty Gas Turbine-Generator with Rigid Coupling Offset (고정 커플링의 오프셋을 갖는 발전용 가스터빈-발전기의 동적 응답해석)

  • Ha, Jin Woong;Jung, Dae Seok
    • The KSFM Journal of Fluid Machinery
    • /
    • v.17 no.4
    • /
    • pp.70-75
    • /
    • 2014
  • In this paper a analysis method is presented to obtain the steady state dynamic response from the finite element based equations of a rotor-bearing system with initial deflection. The method has been applied to analyze the dynamic response of the two-shaft rotor-bearing system with rigid coupling offset in a heavy duty gas turbine-generator. Bumps in the dynamic response of each rotor system have been observed at each critical speed due to the effect of initial deflection for rigid coupling offset. And, the dynamic responses have been shown to reduce for operating condition changes from cold to hot.

Analysis of electro-optic polymer digital optical switch with a coupling region modified for optimum mode coupling (최적의 모드 결합을 얻기 위해 수정된 결합 영역을 갖는 전기광학 폴리머 디지탈 광스위치의 해석)

  • 이상신;신상영
    • Journal of the Korean Institute of Telematics and Electronics D
    • /
    • v.34D no.4
    • /
    • pp.87-93
    • /
    • 1997
  • An electro-optic polymer digital optical switch with a coupling region modified for optimum mode coupling is proposed, and it is analyzed by using the beam propagation method combined with the effective index method. Its modified coupling region is adiabatically introduced along the propagation direction from the branching point of the two waveguides. The structure of the modified coupling region and its refractive index profiles are designed to optimize the mode coupling in the Y-branch waveguide. Therefor, the switching performance of the device may be enhanced with a fixed device length. It is confirmed from the numerical calculation that the drive voltage is reduced by more than 30 percents and te crosstalk is improved by about 8dB.

  • PDF

The Development of Hydraulic-Coupling Experimental Apparatus Using Brake Load and Prediction of Torque Performance (브레이크 부하를 이용한 유체커플링 실험장치 개발과 토크 성능 예측)

  • 박용호;김기홍
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.17 no.5
    • /
    • pp.100-107
    • /
    • 2000
  • The hydraulic couplings have been widely used in industries, automobile, and power-station drives including ships. A mathematical analysis by which the design and application of hydraulic couplings are made is used in conventional design formulae and general roto-dynamic theories. The fluid flow of hydraulic couplings can be considered to have two component, one circumferentially about the coupling axis, and the other passing fluid from the pump to the turbine in the plane of the coupling axis. Tests have been carried out on the full-scale production coupling. The performance test consists of taking measurement of torque of the fluid coupling for three different amount of working fluid inside with various loads to the output shaft. The purpose of this research is to construct the experimental test equipments and to establish a series of performance test for the domestically developed hydraulic couplings, and to obtain experimental results which can be used to improve the performance of the hydraulic coupling and to solve the practical problems confronted in operation.

  • PDF

Characteristics Analysis of Radially Magnetized Tubular type Magnetic Coupling (반경 방향으로 자화된 Tubular 타입 자기 커플링의 특성 해석)

  • Kim, Chang-Woo;Jung, Kyoung-Hun;Choi, Jang-Young
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.64 no.11
    • /
    • pp.1551-1557
    • /
    • 2015
  • Magnetic coupling is used where required high reliability. because magnetic coupling's durability is stronger than mechanical coupling's durability. This paper shows the characteristics of radially magnetized tubular type magnetic coupling by using Analytical method such as space harmonic method. Analytical method was used, to find force characteristics. First, on the basis of the magnetic vector potential and two-dimensional(2-D) polar-coordinate system, the magnetic field solutions of the radially magnetized permanent magnet are obtained. And we obtain the analytical solutions for the flux density produced by permanent magnet. Finally, we can calculate the force by using the Maxwell stress tensor. And then, Finite element method(FEM) is used to validate force characteristics.

Factors Affecting Individuals' Intentions to Discontinue Social Network Services Use

  • Kyungja Park;Joon Koh
    • Asia pacific journal of information systems
    • /
    • v.28 no.1
    • /
    • pp.19-35
    • /
    • 2018
  • This study uses the concepts of mental accounting and coupling in consumption to demonstrate a systematic relationship between behavioral costs, sunk costs, coupling, and user intention to discontinue social network services (SNS) use. An analysis of 213 SNS users found that coupling and sunk costs are two major factors that influence an individual's intention to discontinue SNS use. An interesting finding of this study is that the perception of coupling is created by behavioral costs in the context of an SNS. This finding implies that the source of cost perception when perceiving coupling may differ depending on whether the product or service is traditional or web-based. These results contribute to an expansion of the theoretical discussion of individual-level discontinuance intention after adopting SNS by conceptualizing the perception of coupling.

Bibliographic Author Coupling Analysis: A New Methodological Approach for Identifying Research Trends (서지적 저자결합분석 - 연구동향 분석을 위한 새로운 접근 -)

  • Lee, Jae-Yun
    • Journal of the Korean Society for information Management
    • /
    • v.25 no.1
    • /
    • pp.173-190
    • /
    • 2008
  • Author co-citation analysis(ACA) technique has been widely used for identifying research areas and trends in a discipline. But this technique has some limitations, mainly due to citation delay, on analyzing current trends and identifying active researchers. In this study, a new method, named as Bibliographic Author Coupling Analysis (BACA), is suggested for overcoming those limitations of author co-citation analysis. BACA is based on Kessler's bibliographic coupling approach and focuses not on documents but on authors. Simply stated, BACA technique assumes that those likewise citing authors have the same research interests. For the purpose of comparing with author co-citation analysis, two preceding studies with author co-citation analysis are reconsidered and re-examined using BACA. The comparing results can be regarded as promising the usefulness of BACA in analyzing current research trends and identifying active researchers.

Coupling Effects in Rainfall-induced Slope Stability Considering Hydro-mechanical Model (강우침투에 의한 비탈면 안정해의 수리-역학적 모델을 이용한 커플링 효과)

  • Kim, Yong-Min;Jeong, Sang-Seom
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.9
    • /
    • pp.5-15
    • /
    • 2015
  • In this study, rainfall-induced slope stability and coupling effect are investigated using hydro-mechanical finite element model. This model is developed by formulating constitutive and coupled balance equations and is verified by comparing the numerical results with field matric suction. The homogeneous soil layer (soil column) and soil slope are modeled by this model, and the results of variation in matric suction, mean effective stress, porosity, displacement, factor of safety are compared with those of staggered analysis. It is found that the vertical and horizontal displacement from coupling analysis considering change in porosity is larger than that of staggered analysis. The displacement and matric suction from coupling analysis by rainfall infiltration can affect slope instability, which shows a progressive failure behavior. The lowest factor of safety is observed under short-term rainfall. This results confirm the fact that coupling analysis is needed to design soil slope under severe rain condition.

Dynamic Analysis of Tie-rod-fastened Rotor Considering Elastoplastic Deformation (탄소성 변형을 고려한 타이로드 고정 회전체의 동역학 해석)

  • Dongchan Seo;Kyung-Heui Kim;Dohoon Lee;Bora Lee;Junho Suh
    • Tribology and Lubricants
    • /
    • v.40 no.1
    • /
    • pp.8-16
    • /
    • 2024
  • This study conducts numerical modeling and eigen-analysis of a rod-fastened rotor, which is mainly used in aircraft gas turbine engines in which multiple disks are in contact through curvic coupling. Nayak's theory is adopted to calculate surface parameters measured from the tooth profile of the curvic coupling gear. Surface parameters are important design parameters for predicting the stiffness between contact surfaces. Based on the calculated surface parameters, elastoplastic contact analysis is performed according to the interference between two surfaces based on the Greenwood-Williamson model. The equivalent bending stiffness is predicted based on the shape and elastoplastic contact stiffness of the curvic coupling. An equation of motion of the rod-fastened rotor, including the bending stiffness of the curvic coupling, is developed. Methods for applying the bending stiffness of a curvic coupling to the equation of motion and for modeling the equation of motion of a rotor that includes both inner and outer rotors are introduced. Rotordynamic analysis is performed through one-dimensional finite element analysis, and each element is modeled based on Timoshenko beam theory. Changes in bending stiffness and the resultant critical speed change in accordance with the rod fastening force are predicted, and the corresponding mode shapes are analyzed.

COUPLING LOSS ANALYSIS OF SUPERCONDUCTING WIRE (다심 초전도 선재의 결합손실 해석)

  • Lee, J.K.;Hahn, S.Y.
    • Proceedings of the KIEE Conference
    • /
    • 1991.11a
    • /
    • pp.119-121
    • /
    • 1991
  • Multifilamentary superconducting wires exposed to an alternating field generate the coupling loss and hysteresis loss. The geometric shapes of multifilamentary superconducting wire are very complicate, and loss generating mechanism is too. In this paper, coupling loss of superconducting wire in case of twelve filament is calculated by two dimensional numerical analysis, and compared with value of conventional formulus. The basic idea of this calculating method is potential difference of external transverse field.

  • PDF