• Computational Structural Engineering
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• v.11 no.1
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• pp.179-190
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• 1998

A geometrically nonlinear finite element formulation of spatial cable networks is presented using two cable elements. Firstly, derivation procedures of tangent stiffness and mass matrices for the space truss element and the elastic catenary cable element are summarized. The load incremental method based on Newton-Raphson iteration method and the dynamic relaxation method are presented in order to determine the initial static state of cable nets subjected to self-weights and support motions. Furthermore, static non-linear analysis of cable structures under additional live loads are performed based on the initial configuration. Challenging example problems are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate static nonlinear behaviors of cable nets.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.05a
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• pp.30-35
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• 1996

An elastohydrodynamic lubrication (EHL) analysis for an axially crown profiled cylindrical roller is carried out using a finite difference method and the Newton-Raphson method. Variations of the minimum film thickness with dimensionless parameters show considerably different from those of infinite solutions.

• Journal of Electrical Engineering and Technology
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• v.2 no.3
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• pp.312-319
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• 2007

The solution of the power flow is one of the most important problems in electrical power systems. These traditional methods such as Gauss-Seidel method and Newton-Raphson (NR) method have had drawbacks up to now such as initial values, abnormal operating solutions and divergences in heavy loads. In order to overcome theses problems, the power flow solution incorporating genetic algorithm (GA) is introduced in this paper. General operator of genetic algorithm, arithmetic crossover, and non-uniform mutation operator of GA are suggested to solve the power flow problem. While abnormal solution cannot be obtained by a NR method, multiple power flow solution can be obtained by a GA method. With a heavy load, both normal solution and abnormal solution can be obtained by a proposed method. In this paper, a floating number representation instead of the binary number representation is introduced for accuracy. Simulation results have been compared with traditional methods.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.161-166
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• 2002

Low-tension cables have been increasingly used in recent years due to deep-sea developments and the advent of synthetic cables. In the case of low-tension cables, large displacements may happen due to relatively small restoring forces of tension and thus the effects of fluid and geometric non-linearities become predominant. In this study, three-dimensional (3-D) dynamic behavior of a towed low-tension cable with non-uniform characteristics is numerically analyzed by considering fluid and geometric non-linearities and bending stiffness. A Fortran program is developed by employing a finite difference method. In the algorithm, an implicit time integration and Newton-Raphson iteration are adopted. For the calculation of huge size of matrices, block tri-diagonal matrix method is applied, which is much faster than the well-known Gauss-Jordan method in two point boundary value problems. Some case studies are carried out and the results of numerical simulations are compared with a in-house program of WHOI Cable with good agreements.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.2
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• pp.14-26
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• 2002

A new model for degenerate semiconductor quantum well devices was developed. In this model, the multi-subband Boltzmann transport equation was formulated by applying the Pauli exclusion principle and coupled to the Schrodinger and Poisson equations. For the solution of the resulted nonlinear system, the finite difference method and the Newton-Raphson method was used and carrier energy distribution function was obtained for each subband. The model was applied to a Si MOSFET inversion layer. The results of the simulation showed the changes of the distribution function from Boltzmann like to Fermi-Dirac like depending on the electron density in the quantum well, which presents the appropriateness of this modeling, the effectiveness of the solution method, and the importance of the Pauli -exclusion principle according to the reduced size of semiconductor devices.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.4 no.4
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• pp.127-135
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• 1984

This paper considers the problem of optimum shaping of steel arches subjected to general loading. The weight of arches is considered as the objective function and the appropriate combinations of section forces, material volume, arc length, and closed section area of arches are considered as the stress constraints. The shape optimization problems are formulated in terms of the design variables of sectional areas of each element. First the cost sensitivity of the design is investigated. Then the investigation comprises the search for the optimum arch form as well as the optimum area distribution along the arch. Two spaces of shape optimization algorithm will be treated, the first space corresponding to the section optimization by the Modified Newton Raphson Method, and the second space to the coordinate optimization by the Powell Method. The optimization algorithm is evaluated and the optimum span-rise ratios for the given arches are evaluated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.4
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• pp.15-25
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• 1989

This paper presents the results of the numerical analysis on the behavior of cable-stayed bridge considering geometric nonlinearity of cables. Finite element method is used and geometric nonlinearities are considered on the analysis of cable-stayed bridge. The governing equilibrium equations are derived by the principle of virtual work, and modified Newton-Raphson method and Newmark-${\beta}$ method are employed in response calculations. The validity of this study is demonstrated by comparing the examples with analytical results by other method and testing results.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.5-8
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• 1986

The simulation algorithm for all kinds of robots with arbitrary degrees of freedom which are combined with revolute joints or prismatic joints, or combinations was studied and implemented. This simulation package is composed of trajectory planning routine, control routine, kinematics routine using Newton-Raphson method, dynamics based on Newton-Euler method with four-bar linkage analysis, input routine and output routine.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.3 no.4
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• pp.244-254
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• 1991

The numerical analysis on tile behaviour of mooring system in the offshore guyed tower is presented. The governing equilibrium equations are derived by the principle of virtual work. The drag and inertia effects of fluid are included in a Morrison type equation. The finite element method is used in the computation. Geometric nonlinearities for the analysis of the mooring line are considered in which both modified Newton-Raphson method and Newmark-$\beta$ method are employed. Numerical experiments show the validity and the capability of the developed mathematical formulation.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1975-1981
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• 1991

A new numerical solution of the elastohydrodynamic lubrication(EHL) problem of an axially profiled cylindrical roller is presented. A finite difference method and the Newton-Raphson method are used to solve the nonlinear system equations. A non-uniform grid system is adopted to reduce the number of grid points and to obtain accurate solution. For two different types of profiles which have similar elastostatic pressure distribution, the EHL results show large differences. Especially the difference in film shape is larger than in pressure distribution. Therefore, the magnitude of the minimum film thickness should be a major criteria to design the axial profile of the roller. Variations of the minimum film thickness with dimensionless parameters show considerably different behavior from those of infinite solution and show a good agreement with the experimental data in literatures. Present numerical scheme can be used generally in the analysis of three-dimensional EHL problem.