• Title/Summary/Keyword: coupling method

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The characteristic analysis of contact-less Power supply by 3D finite element method

  • Park, Han-Seok;Cho, Yun-Hyun;Jung, Hong-Sub;Woo, Kyung-il;Kim, Kyung-Ho
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.1
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    • pp.145-151
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    • 2004
  • This paper proposes the calculation method of magnetic coupling coefficient of contact-less power supply by the 3D finite element method with a variation of the secondary core position. The primary, secondary self and leakage inductances and the capacitances of a resonant circuit are calculated by the finite element analysis results. The magnetic coupling coefficients are obtained also. The power factors are obtained by simulation for the magnetic coupling coefficients and compared.

A real-time hybrid testing method for vehicle-bridge coupling systems

  • Guoshan Xu;Yutong Jiang;Xizhan Ning;Zhipeng Liu
    • Smart Structures and Systems
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    • v.33 no.1
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    • pp.1-16
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    • 2024
  • The investigation on vehicle-bridge coupling system (VBCS) is crucial in bridge design, bridge condition evaluation, and vehicle overload control. A real-time hybrid testing (RTHT) method for VBCS (RTHT-VBCS) is proposed in this paper for accurately and economically disclosing the dynamic performance of VBCSs. In the proposed method, one of the carriages is chosen as the experimental substructure loaded by servo-hydraulic actuator loading system in the laboratory, and the remaining carriages as well as the bridge structure are chosen as the numerical substructure numerically simulated in one computer. The numerical substructure and the experimental substructure are synchronized at their coupling points in terms of force equilibrium and deformation compatibility. Compared to the traditional iteration experimental method and the numerical simulation method, the proposed RTHT-VBCS method could not only obtain the dynamic response of VBCS, but also economically analyze various working conditions. Firstly, the theory of RTHT-VBCS is proposed. Secondly, numerical models of VBCS for RTHT method are presented. Finally, the feasibility and accuracy of the RTHT-VBCS are preliminarily validated by real-time hybrid simulations (RTHSs). It is shown that, the proposed RTHT-VBCS is feasible and shows great advantages over the traditional methods, and the proposed models can effectively represent the VBCS for RTHT method in terms of the force equilibrium and deformation compatibility at the coupling point. It is shown that the results of the single-degree-of-freedom model and the train vehicle model are match well with the referenced results. The RTHS results preliminarily prove the effectiveness and accuracy of the proposed RTHT-VBCS.

Palladium-Catalyzed Coupling between Quinolone Moieties and Heteroacyl Stannes - Synthesis of C-7 Heteroacyl Quinolone Derivatives

  • 함원훈;양재권;임태균
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.221-221
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    • 1994
  • The cross-coupling reaction of organo tin reagents with a variety of organic halides, catalyzed by palladium, provides a novel method for generating a carbon-carbon bond. We use this method for antibacterial agents, and synthesis of new quinolone derivatives which have carbon-carbon bond at C-7 position of general quinolone moieties. Aryl tin, quinolone moieties, and palladium catalyst were refluxed in DMF to afford new quinolone derivatives. This palladium catalyzed coupling reactions have capacity for further synthetic elaboration.

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GRADIENT PROJECTION METHODS FOR THE n-COUPLING PROBLEM

  • Kum, Sangho;Yun, Sangwoon
    • Journal of the Korean Mathematical Society
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    • v.56 no.4
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    • pp.1001-1016
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    • 2019
  • We are concerned with optimization methods for the $L^2$-Wasserstein least squares problem of Gaussian measures (alternatively the n-coupling problem). Based on its equivalent form on the convex cone of positive definite matrices of fixed size and the strict convexity of the variance function, we are able to present an implementable (accelerated) gradient method for finding the unique minimizer. Its global convergence rate analysis is provided according to the derived upper bound of Lipschitz constants of the gradient function.

Optimal extended homotopy analysis method for Multi-Degree-of-Freedom nonlinear dynamical systems and its application

  • Qian, Y.H.;Zhang, Y.F.
    • Structural Engineering and Mechanics
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    • v.61 no.1
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    • pp.105-116
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    • 2017
  • In this paper, the optimal extended homotopy analysis method (OEHAM) is introduced to deal with the damped Duffing resonator driven by a van der Pol oscillator, which can be described as a complex Multi-Degree-of-Freedom (MDOF) nonlinear coupling system. Ecumenically, the exact solutions of the MDOF nonlinear coupling systems are difficult to be obtained, thus the development of analytical approximation becomes an effective and meaningful approach to analyze these systems. Compared with traditional perturbation methods, HAM is more valid and available, and has been widely used for nonlinear problems in recent years. Hence, the method will be chosen to study the system in this article. In order to acquire more suitable solutions, we put forward HAM to the OEHAM. For the sake of verifying the accuracy of the above method, a series of comparisons are introduced between the results received by the OEHAM and the numerical integration method. The results in this article demonstrate that the OEHAM is an effective and robust technique for MDOF nonlinear coupling systems. Besides, the presented methods can also be broadly used for various strongly nonlinear MDOF dynamical systems.

Coupling of Meshfree Method and Finite Element Method for Dynamic Crack Propagation Analysis (무요소법과 유한요소법의 결합에 의한 동적균열전팍문제의 해석)

  • 이상호;김효진
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2000.04b
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    • pp.324-331
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    • 2000
  • In this study, a new algorithm analyzing dynamic crack propagation problem by the coupling technique of Meshfree Method and Finite Element Method is proposed. The coupling procedure of two methods is presented with a short description of Meshfree Method especially, Element-free Galerkin (EFG) method. The elastodynamic fracture theory is presented, and a numerical implementation procedure for dynamic fracture analysis by Meshfree Method is also discussed. A couple of dynamic crack propagation problems illustrate the performance of the propsed technique. The accuracy of numerical solutions by the developed algorithm are compared with those of analytical solutions and experimental ones.

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Free Vibration Analysis of an Annular Plate by the Independent Coordinate Coupling Method (독립좌표연성법을 이용한 원환판의 자유진동해석)

  • Heo, Seok;Kwak, Moon-K.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.5
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    • pp.564-571
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    • 2008
  • This paper is concerned with the free vibration analysis of an annular plate with boundary conditions of simply supported-free, clamped-free and free-free, respectively. Exact solutions for the natural frequency and mode of an annular plate can be obtained by solving the differential equation but other methods such as the Rayleigh-Ritz method and the finite element method can be also used. In this research, we applied the Independent Coordinate Coupling Method(ICCM) to the annular plate and prove that the ICCM can accurately predict the natural frequency and mode shape of the annular plate. The numerical results show that the ICCM can be used effectively for the free vibration problem of plate with a hole compared to the Rayleigh-Ritz method and the finite element method.

Nonlinear behavior of deep reinforced concrete coupling beams

  • Zhao, Z.Z.;Kwan, A.K.H.
    • Structural Engineering and Mechanics
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    • v.15 no.2
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    • pp.181-198
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    • 2003
  • Six large scale models of conventionally reinforced concrete coupling beams with span/depth ratios ranging from 1.17 to 2.00 were tested under monotonically applied shear loads to study their nonlinear behavior using a newly developed test method that maintained equal rotations at the two ends of the coupling beam specimen and allowed for local deformations at the beam-wall joints. By conducting the tests under displacement control, the post-peak behavior and complete load-deflection curves of the coupling beams were obtained for investigation. It was found that after the appearance of flexural and shear cracks, a deep coupling beam would gradually transform itself from an ordinary beam to a truss composed of diagonal concrete struts and longitudinal and transverse steel reinforcement bars. Moreover, in a deep coupling beam, the local deformations at the beam-wall joints could contribute significantly (up to the order of 50%) to the total deflection of the coupling beam, especially at the post-peak stage. Finally, although a coupling beam failing in shear would have a relatively low ductility ratio of only 5 or even lower, a coupling beam failing in flexure could have a relatively high ductility ratio of 10 or higher.

3-Axis Coupling Controller for High-Precision/High-Speed Contour Machining (고정밀 고속 윤곽가공을 위한 3축 연동제어기)

  • 지성철;구태훈
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.1
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    • pp.40-47
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    • 2004
  • This paper proposes a three-axis coupling controller designed to improve the contouring accuracy in machining of 3D nonlinear contours. The proposed coupling controller is based on an innovative 3D contour error model and a PID control law. The novel contour error model provides almost exact calculation of contour errors in real-time for arbitrary contours and can be integrated with any type of existing interpolator. In the proposed method, three axes of motion are coordinated by the proposed coupling controller along with a proportional controller for each axis. The proposed contour error model and coupling controller are evaluated through computer simulations. The simulation results show that the proposed 3-axis coupling controller with the new contour error model substantially can improve the contouring accuracy by order of magnitude compared with the existing uncoupled controllers in high-speed machining of nonlinear contours.

Effect of a Finite Substrate on the Mutual Coupling of a Pair of Microstrip Patch Antennas Positioned along the E-plane (유한한 기판 크기가 E-평면상에 배열된 두 개의 패치안테나간의 상호결합에 미치는 영향)

  • Kim, Tae-Young;Kim, Gun-Su;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.6
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    • pp.26-34
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    • 2010
  • The mutual coupling of a pair of microstrip patch antennas on a finite grounded dielectric substrate is influenced by the diffracted field of surface waves from the edges of a substrate. The effective dielectric constant of a grounded dielectric substrate determines the distance between the antenna center and the edge of a substrate to obtain the minimum mutual coupling between a pair of microstrip patch antennas. The optimum substrate size with the minimum mutual coupling is easily calculated using the image method. The optimum substrate sizes using the linage method are in good agreement with the results obtained by the full wave simulation.