• Journal of the Computational Structural Engineering Institute of Korea
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• v.13 no.3
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• pp.321-328
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• 2000

An improved formulation of thin-wailed curved beams with variable curvatures based on displacement field considering the second order terms of finite semitangential rotations is presented. From linearized virtual work principle by Vlasov's assumptions, the total potential energy is derived and all displacement parameters and the warping functions are defined at cendtroid axis. In developing the thin-walled curved beam element having eight degrees of freedom per a node, the cubic Hermitian polynomials are used as shape functions. In order to verify the accuracy and practical usefulness of this study, free vibrations and buckling analyses of parabolic and elliptic arche shapes with mono-symmetric sections are carried out and compared with the results analyzed by ABAQUS' shell element.

• Composites Research
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• v.14 no.4
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• pp.1-7
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• 2001

This paper presents the results of an analytical investigation pertaining to the elastic local buckling behavior of asymmetric edge stiffened orthotropic open section structural member under uniform compression. The asymmetric edge stiffener is considered as a beam element neglecting its torsional rigidity. We suggested the analytical model of asymmetric edge stiffeners which is composed of a strip of flange plate, equal width of edge stiffener, and a plate attached at the flange end, and computed the moment of inertia of the stiffener about an axis through the centroid of the ensuing cross-section. Using the derived equation, the local buckling coefficients of asymmetrically edge stiffened orhtotropic I-section columns are predicted and the results are presented in a graphical form.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.1-10
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• 2004

A study on the evaluation of proper spacing and required flexural rigidity of cross beams in composite two I-section steel girder bridges without a lateral and sway bracing system was performed. Specifically, a 2-lane, 40-m simple span bridge and a 3-span continuous (40+50+10m) bridge were designed, and structural analyses under dead load before and after composite, live, wind, and seismic loads were performed using spacing and flexural rigidity or cross beams as parameters. Through parametric analysis, the effect on the stresses due to the combination of loads and live load distribution was investigated. In addition. material and geometric nonlinear analyses under dead load before composite were performed to evaluate the lateral buckling strength of the steel girders and cross beam. Based on the results or such analyses, the proper spacing and flexural rigidity of cross beams at intermediate points and supports were proposed.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.515-522
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• 2005

The ship plating is generally subjected to. combined in-plane load and lateral pressure loads, In-plane loads include axial load and edge shear, which are mainly induced by overall hull girder bending and torsion of the vessel. Lateral pressure is due to. water pressure and cargo. These load components are nat always applied simultaneously, but mare than one can normally exist and interact. Hence, far mare rational and safe design of ship structures, it is af crucial importance to. better understand the interaction relationship af the buckling and ultimate strength far ship plating under combined loads. Actual ship plates are subjected to relatively small water pressure except far the impact load due to. slamming and panting etc. The present paper describes an accurate and fast procedure for analyzing the elastic-plastic large deflection behavior up to. the ultimate limit state of ship plates under combined loads. In this paper, the ultimate strength characteristics of plates under axial compressive loads and lateral pressure loads are investigated through ANSYS elastic-plastic large deflection finite element analysis with varying lateral pressure load level.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.523-533
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• 1997

Current limit state design method for encased composite columns contains irrational and uncertain design equations in defining section and material properties of composite members. Through investigating previous research used in formulating the design equation, this paper explores the irrationality and uncertainty such as 1) transformation of yield stress and elastic modulus for composite section, 2) an equation influencing buckling strength in terms of area rather than moment of inertia, and 3) selection of larger radius of gyration between steel and concrete sections. Improving the design equations this paper proposes two design methods which can be directly used in practical design.

• Magazine of the Korea Concrete Institute
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• v.14 no.2
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• pp.17-23
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• 2002

화재로 인한 건물의 화해 정도는 건축구조불의 안전성에 크게 영향을 미치게 된다. 특히, 철근 콘크리트 구조물이 화재로 인하여 고열을 받게되면, 그 구조적인 내력이 저하되므로, 이에 대한 안전성 검토는 매우 중요하다. 콘크리트의 고온성상은 시멘트의 종류, 골재의 석질. 배합, 함수율, 재령에 따라 달라진다. 또한, 화해를 입은 콘크리트조 건물은 수열조건에 따라 매우 복잡한 양상을 띄게된다. 일반적으로 화재 건물의 콘크리트 부재에서 나타나는 화해는 각 부재의 폭열 또는 콘크리트의 박리에 의한 주근의 노출 등 직접적인 손상과 보의 변형 기둥의 좌굴, 열팽창에 의한 전단균열 등의 2차 적인 피해가 있다. 그 화해 정도는 지진피해의 파괴현상과 유사한 경우도 있다. 이와 같이 콘크리트 부재의 화재 정도를 검토하기 위해서는 콘크리트의 고온성상 파악이 중요하다.(중략)

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.5
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• pp.405-413
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• 2017

In this paper, we study the biaxial buckling analysis of nonlocal MEE(magneto-electro-elastic) nano plates based on the first-order shear deformation theory. The in-plane electric and magnetic fields can be ignored for MEE(magneto-electro-elastic) nano plates. According to magneto-electric boundary condition and Maxwell equation, the variation of magnetic and electric potentials along the thickness direction of the MME plate is determined. In order to reformulate the elastic theory of MEE(magneto-electro-elastic) nano-plate, the nonlocal differential constitutive relations of Eringen is used. Using the variational principle, the governing equations of the nonlocal theory are discussed. The relations between nonlocal and local theories are investigated by computational results. Also, the effects of nonlocal parameters, in-plane load directions, and aspect ratio on structural responses are studied. Computational results show the effects of the electric and magnetic potentials. These computational results can be useful in the design and analysis of advanced structures constructed from MEE(magneto-electro-elastic) materials and may be the benchmark test for the future study.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.159-165
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• 2003

To Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the structure so that it is wide. Especially, the buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct after the buckling behaviour accurately at the stability of the body of ship structure. In this study, examined closely about conduct and secondary buckling after initial buckling of thin plate structure which receive compressive load according to various kinds aspect ratio under simply supported condition that make by buckling formula in each payment in advance nile to place which is representative construction of hull. Analysis method is F.E.M by ANSYS and complicated nonlinear behaviour to analyze such as secondary buckling.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.993-1000
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• 2006

Practical stability design method of main members of cable-stayed bridges is proposed and discussed through a design example. For this purpose, initial tensions of stay cables and axial forces of main members are firstly determined using initial shaping analysis of bridges under dead loads. And then the effective buckling length using system elastic/inelastic buckling analysis and bending moments considering $P-{\delta}-{\Delta}$ effect by second-order elastic analysis are calculated for main girder and pylon members subjected to both axial forces and moments, respectively. Particularly, load combinations of dead and live loads, in which maximum load effects due to live loads are obtained, are taken into account and effects of live loads on effective buckling lengths are investigated.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.691-699
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• 2002

A study on the evaluationof the proper spacing and required bending rigidity of cross beams in composite multiple I-girder bridge without lateral and sway bracing system was performed. For the purpose, a two-lane 40m simple span and 40+50+40m continuous sample bridge with four girders was designed. For the sample bridges, structural analysis under the design loads including dead load before and after composite, live load, and seismic loads has been performed. The material and geometric nonlinear analysis under dead load before composite has also been performed to evaluate lateral buckling strength of the steel-girder-cross beam grillage. Based on the two phase anlayses, proper spacing and bending righidity of cross beams were proposed.