• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.347-354
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• 2006

In this paper, we work with steel circular tubes and propose analysis model which can consider local buckling that it has an effect on failure of steel structures and induce the relation between loading and deformation. First of all, in respect to axial symmetry local buckling, which is simplest case, elasto-plastic behavior acting only axial loads is object Therefore, it suggests analysis model for axial symmetry local buckling. And that is explainable the process from increasing internal force to decreasing passing maximum internal force. Besides, we induce the relation between the axial force and axial deformation.

• 한국공간구조학회논문집
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• 제3권1호
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• pp.69-75
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• 2003

This paper is represented a general equations to obtain the elastic local buckling stresses for the flange and web of H-beam under compression at elevated temperatures and is also developed the software to perform the elastic local buckling analysis at elevated temperatures. Eurocode3 Part 1.2 are used to analyse the decrease in steel yield strength and elastic modulus at elevated temperatures. For design examples of 6 H-beams, the elastic local buckling stresses and critical temperatures for the slenderness ratio $(b/t_f\;and\;d/t_w)$ of the flange and web under uniform compression at elevated temperatures have been analysed by a computer program of this paper. It can be seen that the computer analytical results of this study show a good agreement with the experimental results by Wadee.

• 한국공간구조학회논문집
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• 제6권3호
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• pp.77-86
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• 2006

본 논문은 횡하중을 받는 냉간성형 ㄷ 형강보의 응력해석에 관해 다루고 있다. 냉간형강 보에 가해지는 각 하중 레벨에서의 응력을 계산하여 국부좌굴과 횡좌굴을 고려하여 구조해석을 실시하였다. 해석모델은 박벽보의 기본이론에 의해 유도되었으며 1차원 보요소 유한요소해석을 통하여 수치해석을 하였다. 수치해석결과는 AISI 규준과 비교되었으며, 본 연구에서 제안된 해석모델이 냉간형강보의 처짐뿐 아니라 응력도 매우 정확히 예측함을 알 수 있었다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 추계학술발표대회 논문집
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• pp.91-94
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• 2001

This paper presents the analytical investigation pertaining to the local buckling behavior of orthotropic channel section compression members stiffened with unsymmetric stiffeners at its free edges. In the analysis, tile edge stiffener is modeled as a beam element or a plate element. The result of both cases is presented in graphical form so that the effects of edge stiffeners on the local buckling strength of edge stiffened channel section member can be found.

• 한국강구조학회 논문집
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• 제18권5호
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• pp.597-606
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• 2006

섬유강화 플라스틱은 강재의 단점을 보완할 수 있는 다양한 장점을 가지고 있기 때문에 현재 건설구조재로 사용하기 위한 연구가 활발히 진행되고 있다. 본 연구는 펄트루젼 FRP를 구조압축재로 사용하기 위한 설계식의 개발에 관한 연구의 일부로서 설계강도에 가장 큰 영향을 미치는 요소 중 국부좌굴거동에 관한 연구이다. 직교이방성 판요소로 구성된 압축부재의 설계에서 국부좌굴의 발생 여부, 국부좌굴을 주도하는 판요소의 구별 등은 매우 중요한 설계요소이며, 이러한 거동을 정밀해법에 의해 계산하기란 매우 복잡하고 난해하다. 따라서, 본 연구에서는 펄트루젼 압축부재의 설계규준 개발을 위해 필요한 국부좌굴계수를 정밀해법, 에너지법, 매개변수 해석 등의 방법을 적용하여 정확하면서도 쉽게 직교이방성판의 좌굴계수와 펄트루젼 압축부재의 국부좌굴계수를 계산할 수 있는 근사식을 제안하였으며 제안된 근사식을 사용하여 펄트루젼 압축부재의 국부좌굴발생 여부 및 국부좌굴을 주도하는 판요소를 구별할 수 있는 방법을 제안하였다.

• Structural Engineering and Mechanics
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• 제64권5호
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• pp.621-640
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• 2017

This paper reports the numerical investigation conducted to study the influence of Local-Distortional (L-D) interaction mode buckling on post buckling strength erosion in fixed ended lipped channel cold formed steel columns. This investigation comprises of 81 column sections with various geometries and yield stresses that are carefully chosen to cover wide range of strength related parametric ratios like (i) distortional to local critical buckling stress ratio ($0.91{\leq}F_{CRD}/F_{CRL}{\leq}4.05$) (ii) non dimensional local slenderness ratio ($0.88{\leq}{\lambda}_L{\leq}3.54$) (iii) non-dimensional distortional slenderness ratio ($0.68{\leq}{\lambda}_D{\leq}3.23$) and (iv) yield to non-critical buckling stress ratio (0.45 to 10.4). The numerical investigation is carried out by conducting linear and non-linear shell finite element analysis (SFEA) using ABAQUS software. The non-linear SFEA includes both geometry and material non-linearity. The numerical results obtained are deeply analysed to understand the post buckling mechanics, failure modes and ultimate strength that are influenced by L-D interaction with respect to strength related parametric ratios. The ultimate strength data obtained from numerical analysis are compared with (i) the experimental tests data concerning L-D interaction mode buckling reported by other researchers (ii) column strength predicted by Direct Strength Method (DSM) column strength curves for local and distortional buckling specified in AISI S-100 (iii) strength predicted by available DSM based approaches that includes L-D interaction mode failure. The role of flange width to web depth ratio on post buckling strength erosion is reported. Then the paper concludes with merits and limitations of codified DSM and available DSM based approaches on accurate failure strength prediction.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.319-326
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• 2001

In this paper, 3-D frame design using refined plastic-hinge analysis accounting for local buckling is developed. This analysis accounts for material and geometric nonlinearities of the structural system and its component members. Moreover, the problem associated with conventional refined plastic-hinge analyses, which do not consider the degradation of the flexural strength caused by local buckling, is overcome. Efficient ways of assessing steel frame behavior including gradual yielding associated with residual stresses and flexure, second-order effect, and geometric imperfections are presented. In this study, a model consisting of the width-thickness ratio is used to account for local buckling. The proposed analysis is verified by the comparison of the LRFD results.

• Steel and Composite Structures
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• 제29권3호
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• pp.379-389
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• 2018

In this research, the explicit closed-form local buckling solution of steel plates in contact with concrete, with both loaded and unloaded edges elastically restrained against rotation and subjected to eccentric compression is presented. The Rayleigh-Rize approach is applied to establish the eigenvalue problem for the local buckling performance. Buckling shape which combines trigonometric and biquadratic functions is introduced according to that used by Qin et al. (2017) on steel plate buckling under uniform compression. Explicit solutions for predicting the local buckling stress of steel plate are obtained in terms of the rotational stiffness. Based on different boundary conditions, simply yet explicit local buckling solutions are discussed in details. The proposed formulas are validated against previous research and finite element results. The influences of the loading stress gradient parameter, the aspect ratio, and the rotational stiffness on the local buckling stress resultants of steel plates with different boundary conditions were evaluated. This work can be considered as an alternative to apply a different buckling shape function to study the buckling problem of steel plate under eccentric compression comparing to the work by Qin et al. (2018), and the results are found to be in consistent with those in Qin et al. (2018).

• 한국강구조학회 논문집
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• 제14권1호
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• pp.13-21
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• 2002

본 논문에서는 국부좌굴을 고려하는 개선소성힌지해석법을 이용하여 3차원 강뼈대 구조물의 설계기법을 개발하였다. 본 해석은 구조시스템 및 개별부재의 재료적 기하학적 비선형 거동을 고려한다. 더욱이, 종래의 개선소성힌지해석에서 국부좌굴효과에 의한 휨강도 감소 효과를 고려하지 못한 문제를 해결하였다. 강뼈대 구조물의 잔류응력과 휨에 의한 비선형성 및 기하학적 불완전성에 의한 점진적인 소성화효과를 고려하는 효율적인 방법을 기술하였다. 국부좌굴효과를 고려하기 위하여 단면의 폭-두께비로 구성되는 휨강도 감소모델을 사용하였다. 개발된 개선소성힌지해석법은 LRFD 설계방법과 비교함으로서 검증되었다. 예제해석을 통하여 국부좌굴효과는 개선소성힌지해석법에 고려해야 할 중요한 요소임을 나타내었다. 본 해석은 실제 설계에 활용할 수 있는 효율적이고 신뢰성 있는 방법이다.

• Steel and Composite Structures
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• 제24권3호
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• pp.339-349
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• 2017

In this paper, a conventional refined plastic hinge analysis is improved to account for the effects of local buckling and lateral-torsional buckling. The degradation of flexural strength caused by these effects is implicitly considered using practical LRFD equation. The second-order effect is captured using stability functions to minimize modeling and solution time. An incremental-iterative scheme based on the generalized displacement control method is employed to solve the nonlinear equilibrium equations. A computer program is developed to predict the second-order inelastic behavior of space steel frames. To verify the accuracy and efficiency of the proposed program, the obtained results are compared with the existing results and those generated using the commercial finite element package ABAQUS. It can be concluded that the proposed program proves to be a reliable and effective tool for daily use in engineering design.