• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.49-52
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• 2000

The hole flanging experiments are performed on a flat circular plates with a hole in the center and the flangeability and fracture behavior of TRIP steel and ferrite-bainite duplex steel were examined. Over the ranges of conditions investigated, the flangeability of ferrite-bainite duplex steel is better than TRIP steel and the term 'hole flanging capacity' introduced in this study. Fracture behavior of TRIP steel and ferrite-bainite duplex steel was characterized by petal formation at the edge of flange. In case of crack propagation, crack tip diversion that is supposed to be responsible for flangeability occurs more severely on HSLA Steel.

• Korea-Australia Rheology Journal
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• v.21 no.4
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• pp.245-268
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• 2009

Recent developments in dilute polymer solution rheology are reviewed, and placed within the context of the general goals of predicting the complex flow of complex fluids. In particular, the interplay between the use of polymer kinetic theory and continuum mechanics to advance the microscopic and the macroscopic description, respectively, of dilute polymer solution rheology is delineated. The insight that can be gained into the origins of the high Weissenberg number problem through an analysis of the configurational changes undergone by a single molecule at various locations in the flow domain is discussed in the context of flow around a cylinder confined between flat plates. The significant role played by hydrodynamic interactions as the source of much of the richness of the observed rheological behaviour of dilute polymer solutions is highlighted, and the methods by which this phenomenon can be incorporated into a macroscopic description through the use of closure approximations and multi scale simulations is discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.161-162
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• 2009

In this study, the methodology of calculating the construction loads with considering effects of the shoring stiffness and slab cracks is proposed. Comparisons with the proposed method and the existing methods for construction load calculations were performed for measured shoring loads.

• Journal of the Korean Institute of Navigation
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• v.12 no.2
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• pp.68-101
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• 1988

In spite of the widespread use of stiffend plates in ship structures, it is very difficult to analysis these directly. So, in conventional analysis of plate structures, above structures are used to be idealized as orthotropic plate or grillage structures. Lately, the development of large computers, it is able to apply the optimum techniques to structural design. In this paper, the double bottom structure of Bulk Carrier was idealized into flat grillage which is composed of intersecting beam stiffencers primarily loaded mormal to its surface. And strength analysis was carried out by using the finite element method based on displacement. And further, according to variation of floor space and double tobbon heightm, the optimum design was carrid out by using Hooke and Jeeves direct search method.

• Steel and Composite Structures
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• v.35 no.1
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• pp.43-59
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• 2020

In this study, free vibration analysis of laminated composite parabolic thick plate frames by using finite element method is introduced. Governing equations of an eigenvalue problem are obtained from First Order Shear Deformation Theory (FSDT). Finite element method is employed to obtain natural frequency values from the governing differential equations. The frames consist of two flat square plates and one singly curved plate. Parameters like radii of curvature, aspect ratio, ply orientation and boundary conditions are investigated to understand their effect on dynamic behavior of such a structure. In addition, multi-bay structures of such geometry with different stacking order are also taken into account. The composite frame structures are also modeled and simulated via ANSYS to verify the accuracy of the present study.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.2
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• pp.79-87
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• 2016

Mobile fish-cage was developed assuming a cage net with an enclosed area, which and estimated the hydrodynamic characteristics of the cage through the model experiment. Flux-shielding plates, installed in the bow were compared with the resistance test carried out by making a hole, bilge keel and stud, and basic block flow rate consisting of the results to a flat surface plate. The experimental results confirmed the improved resistance performance effect of 3~6% in the bilge keel and the stud form. To assess the stability of the fish-cage, evaluation of the stability in accordance with the stability criteria for determining the floating docks had confirmed that it satisfied the static stability performance under operating conditions at sea.

• Mass Spectrometry Letters
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• v.7 no.4
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• pp.91-95
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• 2016

In recent years, matrix-free laser desorption ionization (LDI) for mass spectrometry of thermally labile molecules has been an important research subject in the pursuit of new ionization methods to serve as alternatives to the conventional matrix-assisted laser desorption ionization (MALDI) method. While many recent studies have reported successful LDI of thermally labile molecules from various surfaces, mostly from surfaces with nanostructures, understanding of what drives the LDI process still requires further study. This article briefly reviews the thermal aspects involved in the LDI mechanism, which can be characterized as rapid surface heating. The thermal mechanism was supported by observed LDI and postsource decay (PSD) of peptide ions produced from flat surfaces with special thermal properties including amorphous Si (a-Si) and tungsten silicide ($WSi_x$). In addition, the concept of rapid surface heating further suggests a practical strategy for the preparation of LDI sample plates, which allows us to choose various surface materials including crystalline Si (c-Si) and Au tailorable to specific applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.812-815
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• 2002

The shape of K-R curve for an ideally brittle material is flat because the surface energy is an unvaried material property. However, the K-R curve can take on a variety of shapes when nonlinear material behavior accompanies fracture. By the way, a general metallic material is nonlinear, structural steel is such. Therefore, the J-R curve form J-integral value instead of K parameters can be used to evaluate elastic-plastic materials with flaws in terms of ductile fracture that can be significant to design. In this paper, R-curve behaviors form K and J parameter is considered for the precise assessment of fracture analysis, in case of JS-SS400 steels.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.177-184
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• 2005

This paper is concerns with the development of the formulae to predict deformation of curved plate due to line heating. For this purpose thermal elasto-plastic analysis has been carried out for both flat and curved plate models with varying parameters which affect the result of line heating. based on the results of numerical analysis, the formulae for predicting angular deformation has been derived through the regression analysis, which. It has been seen that the present model well agrees with the numerical analysis results and can reflect the curvature effect of plate to be heated. This paper ends with some comments on this formulae.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.2
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• pp.828-834
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• 2019

Researchers have previously proven that the flapping motion of the hydrofoil can convert wave energy into propulsive energy. However, the estimation of thrust forces generated by the flapping foil placed in waves remains a challenging task for ocean engineers owing to the complex dynamics and uncertainties involved. In this study, the flapping foil system consists of a rigid NACA0015 section undergoing harmonic flapping motion and a passively actuated elastic flat plate attached to the leading edge of the rigid foil. We have experimentally measured the thrust force generated due to the flapping motion of a rigid foil attached to an elastic plate in a wave flume, and the effects of the elastic plates have been discussed in detail. Furthermore, an empirical formula was introduced to predict the thrust force of a flapping foil based on our experimental results using multiple regression analysis.