• Journal of Korea Game Society
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• v.9 no.4
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• pp.97-106
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• 2009

In this paper, a realtime approach to the simulation of virtual paper with an adaptive mesh structure is proposed. The proposed method can be applied to arbitrary triangular mesh structures and efficiently produces wrinkles and creases on the paper surface with stable numerical integration and deformation-based mesh refinement. In order to plausibly represent the crumples on the paper object, we employed an adaptive mesh structure with breakable springs. Because the adaptive structure continuously inserts or removes vertices and edges to or from the mesh structure, the conservation of the mass and the momentum should be carefully taken into account for the plausible simulation of the virtual paper. The proposed method produced plausible animation of paper-like thin shell in realtime environments.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.107-113
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• 2015

The goal of this paper is to investigate structural integrity factors of RMI(reflective metal insulation) to confirm the design requirements in nuclear power plant. Currently, a glass wool insulation is using now, but it will gradually be replaced with the reflective metal insulation maded by stainless steel plates. The main function of an insulation is to minimize a heat loss of vessel and pipes in RCS(reactor coolant system). It has to maintain structural a integrity in nuclear power plant life duration. In this study, the structural integrity analysis was carried out both multi-plate and outer shell plate by using a static analysis and experimental test. First, inner multi-plate has a self support structure for being air space. Because the effect of total static weight in multi-layer plate is low, a plate collapse possibility is not high. Considering optimum thin plate pressing process, it has to pre-check the basic physical properties. Second, the outer segment thickness and stiffener shape are verified by the numerical static analysis, and sample test for both type of panel and cylindrical pipe model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.25-26
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• 2007

Ship are typically thin-walled structures and consists of stiffened plate structure by purpose of required design load and weight reduction etc. Also, a hull structural characteristics are often used in structures with curvature at deck plating with camber, side shell plating at fore and aft parts and bilge circle parts, It have been believed that these structures can be modelled fundamentally by a part of cylinder. Structural component with curvature subjected to combined loading regimes and complex boundary conditions, which can potentially collapse due to buckling. Hence, for more rational and safe design of ship structures, it is crucial importance to better understand the interaction relationship of the buckling and ultimate strength for cylindrically curved plate under these load components. In this study, the ultimate strength characteristic of curved plate under combined load(lateral pressure load + axial compressive load) are investigated through using FEM series analysis with varying geometric panel properties.

• Composites Research
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• v.14 no.6
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• pp.9-15
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• 2001

In the present work, a linear static analysis is presented for thin-walled prismatic box-beams made of generally anisotropic materials. A mixed beam theory has been used to model and carry out the analysis. Several different constitutive assumptions for the shell-wall of the beam section are assessed into the beam formulation. Simple layup cases of box-beams representing bending-torsion or extension-torsion coupled configuration have been considered and tested to clearly show the effects of elastic couplings of the beam. A detailed finite element structural analysis using the MSC/NASTRAN has been carried out to validate the current analytical results. Numerical results show that appropriate assumptions for the constitutive relations are important and crucial for the accurate prediction of beam stiffness constants and also thor the beam behavior.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.9
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• pp.851-858
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• 2008

In this paper, the wrinkling behavior of vertically creased corner-loaded square membranes was studied using geometrically nonlinear post-buckling analysis. The membranes were modeled using shell elements, and the meshes were seeded with semi-random geometrical imperfection to instigate the buckling deformation. A pristine and creased membranes with various initial deployment angles were considered in the analyses and the results were compared. Results showed that local wrinkles initiated near the corner where the higher load was applied, which grew to form a single diagonal global wrinkle as the load ratio increased. It was also found that the local wrinkle initiation and the global wrinkle formation were significantly dependent on the initial deployment angles.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.411-437
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• 2012

In this paper, we propose a continuum mechanics based 3-D beam finite element with cross-sectional discretization allowing for warping displacements. The beam element is directly derived from the assemblage of 3-D solid elements, and this approach results in inherently advanced modeling capabilities of the beam element. In the beam formulation, warping is fully coupled with bending, shearing, and stretching. Consequently, the proposed beam elements can consider free and constrained warping conditions, eccentricities, curved geometries, varying sections, as well as arbitrary cross-sections (including thin/thick-walled, open/closed, and single/multi-cell cross-sections). We then study the modeling and predictive capabilities of the beam elements in twisting beam problems according to geometries, boundary conditions, and cross-sectional meshes. The results are compared with reference solutions obtained by analytical methods and solid and shell finite element models. Excellent modeling capabilities and solution accuracy of the proposed beam element are observed.

• Structural Engineering and Mechanics
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• v.34 no.4
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• pp.491-505
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• 2010

A computational analysis of the nonlinear free vibration of corrugated annular plates with shallow sinusoidal corrugations under uniformly static ambient temperature is examined. The governing equations based on Hamilton's principle and nonlinear bending theory of thin shallow shell are established for a corrugated plate with a concentric rigid mass at the center and rotational springs at the outer edges. A simple harmonic function in time is assumed and the time variable is eliminated from partial differential governing equations using the Kantorovich averaging procedure. The resulting ordinary equations, which form a nonlinear two-point boundary value problem in spatial variable, are then solved numerically by shooting method, and the temperature-dependent characteristic relations of frequency vs. amplitude for nonlinear vibration of heated corrugated annular plates are obtained. Several numerical results are presented in both tabular and graphical forms, which demonstrate the accuracy of present method and illustrate the amplitude frequency dependence for the plate under such parameters as ambient temperature, plate geometry, rigid mass and elastic constrain.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.33-36
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• 2008

It is generally known that a shell in the form of layered structures stacked up thin elements by organic adhesives has high resistance capacity against static and impact loading. The complex materials such as these diversified layered structures are more reliable and efficient to the impact loading than the single material. In this study, the segmented composites in the shape of a beam were made, using mortar and concrete block and tested under static and impact loading in order to develop the complex materials in the form of layered structures as the segmented composites to resist impact loading. And it compared to the normal concrete beams having the same compressive strength to evaluate the differences in their performance and failure modes.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.73.1-73.1
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• 2012

We present the results of dust scattering simulations carried out for the Orion Eridanus Superbubble region by comparing them with observations made in the far-ultraviolet. The albedo and the phase function asymmetry factor (g-factor) of interstellar grains were estimated as well as the distance and thickness of the dust layers. The results are: 0.39-0.45 for the albedo and 0.25-0.65 for the g-factor, in good agreement with previous determinations and theoretical predictions. The distance of the assumed single dust layer, modeled for the Orion Molecular Cloud Complex, was estimated to be -110 pc and the thickness ranged from -130 at the core to -50 pc at the boundary for the region of the present interest, implying that the dust cloud is located in front of the Superbubble. The simulation result also indicates that a thin (-10 pc) dust shell surrounds the inner X-ray cavities of hot gas at a distance of -70-90 pc.

• International Journal of High-Rise Buildings
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• v.9 no.1
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• pp.53-60
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• 2020

"A practical architect might not unnaturally conceive the idea of erecting a vast edifice whose frame should be entirely of iron, and clothing the frame--preserving it--by means of a casing of stone…that shell must be regarded only as an envelope, having no function other than supporting itself..." --Viollet-le-Duc, 1868. Viollet-le-Duc's recipe for an encased iron frame foresaw the separation of structural and enclosing functions into discrete systems. This separation is an essential characteristic of skyscrapers today, but at the time of his writing cast iron's brittle nature meant that iron frames could not, on their own, resist lateral forces in tall structures. Instead, tall buildings had to be braced with masonry shear walls, which often also served as environmental enclosure. The commercial availability of steel after the 1880s allowed for self-braced metal frames while parallel advances in glass and terra cotta allowed exterior walls to achieve vanishingly thin proportions. Two Chicago buildings by D.H. Burnham & Co. were the first to match a frame "entirely of iron" with an "envelope" supporting only itself. The Reliance Building (1895) was the first of these, but the Fisher Building (1896) more fully exploited this new constructive typology, eschewing brick entirely, to become the first "building without walls," a break with millennia of tall construction reliant upon masonry