• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.134.2-134
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• 2002

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.220-223
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• 1985

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.728-730
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• 1987

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.10a
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• pp.237.2-237
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• 1999

• Journal of Ocean Engineering and Technology
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• v.14 no.2
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• pp.112-116
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• 2000

To determine a preliminary hull form with a minimum viscous resistance this study considers the systematic variations of full form and calculations of the viscous resistance for varied hull forms. A preliminary hull form can be determined from a parametric study of viscous resistance.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.1
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• pp.39-46
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• 2015

The purpose of this study is to analyze the deflection of the prestressed beams. In this paper, a finite element model for deflections of prestressed beams is presented. Proposed finite element model was verified comparing with existing experimental results, and it showed a good agreement with the experimental results. Also, a parametric study has been conducted to analyze the influence of eccentricity, span-depth ratio, and prestressing force. The finite element model results were compared with hand calculation results. Deflections were increased as the eccentricity decreases, the span-depth ratio increases, and the prestressing force decreases. Hand calculation overestimated the deflection when the eccectricity or prestressing force is too small.

• Computational Structural Engineering
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• v.5 no.1
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• pp.119-132
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• 1992

The objective of this study is to perform extensive parametric studies of the lateral-torsional buckling of short 1-beams under repeated loadings, and to gain a further insight into the lateral-torsional beam buckling problem. A one-dimensional geometrically (fully) nonlinear beam model is used, which includes superposed infinitesimal transverse warping deformation in addition to finite torsional warping deformation. A multiaxial cyclic plasticity model is also implemented to better represent cyclic metal plasticity in conjunction with a consistent return mapping algorithm. The general response for the lateral-torsional buckling of short I-beams under repeated loadings is examined through several parametric studies around the standard case : the material yield strength, the yield plateau, the strain hardening, the kinematic hardening, the residual stresses, the load eccentricity with respect to the shear center, the height of the load with respect to the cross-section of the beam, the location of the load along the length of the beam, the dimensions of the cross-section of the beam and the fixity of the supported end remote from the load.

• Journal of Ocean Engineering and Technology
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• v.28 no.5
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• pp.411-422
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• 2014

A helideck is a very valuable offshore structure for the take-off and landing of a helicopter. In order to design a helideck, the design parameters and various loads defined by the regulations related to the design of a helideck should be applied. In this study, a risk analysis was performed based on the helicopter accidents for seven years, and the frequency and possible reasons for accidents involving helidecks were investigated. In addition, a finite element analysis of a steel helideck mounted on the upper deck of a ship (shuttle tanker) was performed with the load that should be considered when designing a helideck. Based on the results, a parametric study of helideck was carried out by applying a variety of design parameters, and an improved helideck design was presented. This improved helideck reduced the steel used by up to 24% compared to the initial helideck design, and the results of a finite element analysis were analyzed and compared with those of the initial analysis.

• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.21-31
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• 2017

Engineered Cementitious Composite (ECC) is a special class of the new generation of high performance fiber reinforced cementitious composites (HPFRCC) featuring high ductility with relatively low fiber content. In this research, the mechanical performance of ECC beams will be investigated with respect to the effect of slag and aggregate size and amount, by employing nonlinear finite element method. The validity of the models was verified with the experimental results of the ECC beams under monotonic loading. Based on the numerical analysis method, nonlinear parametric study was then conducted to evaluate the influence of the ECC aggregate content (AC), ECC compressive strength ($f_{ECC}$), maximum aggregate size ($D_{max}$) and slag amount (${\phi}$) parameters on the flexural stress, deflection, load and strain of ECC beams. The simulation results indicated that when increase the slag and aggregate size and content no definite trend in flexural strength is observed and the ductility of ECC is negatively influenced by the increase of slag and aggregate size and content. Also, the ECC beams revealed enhancement in terms of flexural stress, strain, and midspan deflection when compared with the reference beam (microsilica MSC), where, the average improvement percentage of the specimens were 61.55%, 725%, and 879%, respectively. These results are quite similar to that of the experimental results, which provides that the finite element model is in accordance with the desirable flexural behaviour of the ECC beams. Furthermore, the proposed models can be used to predict the flexural behaviour of ECC beams with great accuracy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.3
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• pp.329-335
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• 2014

A maglev vehicle of middle-low speed subjected to both a lift force and a guidance force by a U-shaped single electromagnet is operated over a curved guideway without a guidance controller. Therefore, it is required to carefully decide the curve shape for preventing contact between the vehicle and the guiderail for the case that a Maglev vehicle is operated over a curved guideway with a small radius. Specifically, the shape of the transition curve is very important from the stability viewpoint. This study analyzes the influence of curve shape on maglev stability through parametric composition of the transition curve during vehicle guidance. To this end, a multibody dynamics-based threedimensional Maglev vehicle model was developed. The model was integrated with the vehicle, curved guideway, electromagnets, and their controllers. Using this model, a realistic parametric study including the curved guideway was carried out. The results of research should be considered usefully in the design of bogies and the curve shape.