• Journal of Korean Association for Spatial Structures
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• v.12 no.3
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• pp.55-62
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• 2012

본 연구는 온도 증가에 따른 압축을 받는 H형 강재의 플랜지와 웨브의 국부 및 전체좌굴응력 내화해석 프로그램 개발과 플랜지와 웨브가 항복파괴전에 국부좌굴이 일어나지 않을 한계 판폭두께비의 상관값을 구하는 프로그램을 개발하는 것이다. 고온에서의 강재의 응력-변형도 관계식은 EC3:Part 1.2를 근거로 하였으며, 비교, 검토를 위하여 영국 BS5950의 강재를 대상으로 온도 증가에 따른 압축을 받는 강재의 플랜지와 웨브의 파괴온도와 하중을 본 연구의 내화해석 프로그램으로 예측하였다. 본 연구는 좌굴 및 항복에 대한 내화해석 프로그램을 개발하는 것을 목적으로 하고 적용 예를 통하여 좌굴 및 한계 판폭두께비를 분석하고 개발 프로그램의 타당성을 검토하였다.

• Journal of Korean Society of Steel Construction
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• v.17 no.6 s.79
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• pp.707-715
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• 2005

Corrugated webs have been used for composite prestressed concrete box girder bridges. Innovative steel plate girders using corrugated webs have been proposed. It has been found that analytical and experimental researches conducted to determine the strength of trapezoidally corrugated webs can fail with respect to three different buckling modes: local, global, and interactive shear buckling. Shear buckling capacity equations based on classical and orthotropic plate buckling theories have been proposed,but these equations show some differences. In this paper, geometric parameters that influence interactive shear buckling behavior with interaction effects are identified via extensive bifurcation buckling analysis using the finite element meth.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.491-498
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• 2005

This study involves the development of a computer program to analyze the local buckling stresses for the flange and the web of I-beams under compression at elevated temperatures, and the optimization algorithm to analyze the optimum width-thickness ratios which does not occur their local buckling prior to yield failure. The high-temperature stress-strain relationships of steel used in this study were based on EC3 (Eurocode3) Part1.2 (2000b). In this study, the local buckling stresses and the optimum width-thichness ratios were analyzed considering the influences of the yield stress, local buckling coefficients and width-thickness ratios of the flange and the web. Design examples show the applicability of the computer program developed in this study.

• Journal of Korean Society of Steel Construction
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• v.25 no.5
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• pp.579-585
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• 2013

Shear buckling stresses of steel pipes due to the lateral forces have been analyzed via parametric analysis. Detailed FEM models are prepared, and steel types, thickness, radii and length of steel pipes are selected as parameters. STK400, STK490 and SM570 are used and the thickness of pipe is 2mm and 40mm. The radii(R) and lengths(L) are determined based on the values satisfying the following relationship as R/t=20~400 and L/R=1~3. The shear buckling stresses decrease for all types of considered steels as R/t increase from 20 to 200. High strength steels are more sensitive to R/t, and also have an bigger effect on shear buckling stresses than low strength steels. It is found that shear buckling stresses decrease as L/R increases, showing that the steel pipes become weak as the length of the steel pipe increases.

• Journal of Korean Society of Steel Construction
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• v.13 no.2
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• pp.191-200
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• 2001

This paper presents buckling analysis of the cylindrical shell subjected to axial loads using numerical method. The modeling method, appropriate element type, and number of element are recommended by comparing with analytical solution. Based on the parametric study, buckling stress decreases significantly as the diameter-thickness ratio increases. These results are different from those obtained from buckling analysis of columns. The number of buckling half-wave in circumferential direction decreases as the diameter-height ratio increases. Buckling stress increases 1~2% as the thickness of base plate increases. Therefore the effect of base plate on buckling strength for cylindrical shell can be disregarded. Buckling stress significantly decreases as the amplitude of initial geometric imperfection used for calculating buckling stress is developed and it shows a good agreement with numerical results.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.51-60
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• 2004

The stress analysis of cold-formed channel section steel beams under transverse load was conducted. The local buckling effect was included in the analysis using effective area concept. The proposed analytical model is capable of predicting accurate normal stress in the beam due to various behaviors including biaxial bending and warping. It was found to be appropriate for predicting stresses as well as deflection in the beam. A finite element model was developed to solve the analytical model.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.407-421
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• 1998

The purpose of this paper is to provide and verify an analytical method, based on the spline finite strip method, which can be used to investigate the buckling mode and stress of thin-walled steel sections. Geometric imperfection and initial stress of plates and plate assemblies, which are resulted from various preloadings and may cause prebuckling deformations before buckling, are included in the analysis. Material nonlinearity and residual stress are also considered. It can be applied to sections with simple or non-simple boundary conditions and arbitrary loading. The method has been applied to investigate the buckling behavior of plates and plate assemblies which are subjected to compression with initial imperfections and residual stresses.

• Journal of Korean Association for Spatial Structures
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• v.6 no.3 s.21
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• pp.77-86
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• 2006

The stress analysis of cold-formed channel section steel beams under transverse load is presented. The local buckling as well as the lateral buckling effects are included in the analysis. The analytical model is developed based on the thin-walled beam theory, and a one-dimensional finite element model is formulated to solve the analytical model. Numerical results are compared with AISI code. It shows that the proposed model is appropriate for predicting of stress as well as deflection of the cold-formed channel section beam.

• Composites Research
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• v.13 no.5
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• pp.37-43
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• 2000

In this paper an analytical investigation pertaining to the elastic shear buckling behavior of transversely stiffened orthotropic plate under in-plane shear forces is presented. All edges of plate are assumed to be simply supported and the evenly placed stiffener is considered as a beam element neglecting its torsional rigidity. For the solution of the problem Rayleigh-Ritz method is employed. Using the derived equation, the limit of buckling stress of transversely stiffened plate is suggested as a graphical form. Based on the limit of buckling stress of stiffened plate, graphical form of results for finding the required stiffener rigidity is presented when one and two stiffeners are located, respectively.

• Journal of Korean Society of Steel Construction
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• v.10 no.3 s.36
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• pp.393-406
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• 1998

In this study buckling behavior of orthotropic plate with a longitudinal stiffener under in-plane linearly distributed loads is investigated. All edges of plate are assumed to be simply supported and the stiffener is considered as a beam element. For the equation of buckling analysis Rayleigh-Ritz method is employed. The upper limit of the critical stress at various location of stiffener is determined by using Lagrangian multiplier method. Buckling analysis is performed for the various position of stiffener and for the various width ratios between plate and stiffener. The parametric study shows that, when four edges of plate are simply supported, the most effective position for a longitudinal stiffener is at the location of which the upper limit of the stress is the maximum.