• 산업기술연구
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• 제1권
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• pp.9-16
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• 1981

In the steel Structural design, buckling is the main factor to determine size, particularly in compression member. Buckling may sometimes occur in the form of wrinkles in thin elements, such as webs, flanges, and other parts that make up a section. This phenomenon is called local buckling. The strength of the steel and the rigidity of the frame are considerably deteriorated by the local buckling. The specimens used for this experiments, H-Shape Steel beams composed by fillet-welding, are dessified classified into two groups, ie one for web test and another for flange fest. The aim of this study is to define the influences by the local bucking on the vesisting forces, deformation and the phenomena of the internal forces in the section, and to collect the basic data for design of steel beams.

• Structural Engineering and Mechanics
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• 제81권2호
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• pp.231-242
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• 2022

Numerical solutions for the linear buckling behavior of thin-walled circular hollow section members (CHS) with and without longitudinal stiffeners are presented using the semi-analytical finite strip method (SAFSM) which is developed based on Marguerre's shallow shell theory and Kirchhoff's assumption. The formulation of 3-nodal line finite strip is presented. The CHS members subjected to uniform axial compression, uniform bending, and combination of compression and bending. The buckling behavior of CHS is investigated through buckling curves which relate buckling stresses to lengths of the member. Effects of longitudinal stiffeners are studied with the change of its dimensions, position, and number.

• Steel and Composite Structures
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• 제2권4호
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• pp.297-314
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• 2002

An energy method of analysis is presented which can be used to study the inelastic lateral-distortional buckling of hot-rolled I-sections continuously restrained at the level of the tension flange. The numerical modelling leads to the incremental and iterative solution of a fourth-order eigenproblem, with very rapid solutions being obtainable, so as to enable a study of the factors that influence the strength of continuously restained I-beams to be made. Although hot-rolled I-sections generally have stocky webs and are not susceptible to reductions in their overall buckling loads as a result of cross-sectional distortion, the effect of elastic restraints, particularly against twist rotation, can lead to buckling modes in which the effect of distortion is quite severe. While the phenomenon has been studied previously for elastic lateral-distortional buckling, it is extended in this paper to include the constitutive relationship characteristics of mild steel, and incorporates both the so-called 'polynomial' and 'simplified' models of residual stresses. The method is validated against inelastic lateral-torsional buckling solutions reported in previous studies, and is applied to illustrate some inelastic buckling problems. It is noted that over a certain range of member slenderness the provisions of the Australian AS4100 steel standard are unconservative.

• Steel and Composite Structures
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• 제34권4호
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• pp.561-580
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• 2020

Buckling restrained braces (BRBs) were developed as an enhanced alternative to conventional braces by restraining their global buckling, thus allowing development of a stable quasi-symmetric hysteretic response. A wider adoption of buckling restrained braced frames is precluded due to proprietary character of most BRBs and the code requirement for experimental qualification. To overcome these problems, BRBs with capacities corresponding to typical steel multi-storey buildings in Romania were developed and experimentally tested in view of prequalification. In the second part of this paper, a complex nonlinear numerical model for the tested BRBs was developed in the finite element environment Abaqus. The calibration of the numerical model was performed at both component (material models: steel, concrete, unbonding material) and member levels (loading, geometrical imperfections). Geometrically and materially nonlinear analyses including imperfections were performed on buckling restrained braces models under cyclic loading. The calibrated models were further used to perform a parametric study aiming at assessing the influence of the strength of the buckling restraining mechanism, concrete class of the infill material, mechanical properties of steel used for the core, self-weight loading, and frame effect on the cyclic response of buckling restrained braces.

• 한국공간구조학회논문집
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• 제3권2호
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• pp.91-99
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• 2003

The purpose of this study is to analyze the characteristics of the connector having an influence on the elasto-plastic buckling load of ball-jointed single layer latticed domes. As an analytic model, domes are composed of tubular member elements, balls and connectors. The joint system of members in single layer latticed domes has influence on the buckling load. Therefore, in this paper, the variation of the elasto-plastic buckling load by effects of the connectors characteristics is analyzed. The structural behavior of the connector is investigated by following points: (1) the length of rigid zone, (2) looseness of screw and (3) the diameter of connector. In addition, the elasto-plastic buckling analysis is carried out through the variation of the connectors section of yielding part, and then the buckling mode of the dome is examined. As a result, it is emphasized that the characteristics of the connector have significant effects on the buckling load of latticed domes.

• 복합신소재구조학회 논문집
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• 제2권1호
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• pp.15-22
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• 2011

펄트루젼 FRP 구조용 부재는 많은 유용한 역학적, 물리적 성질 때문에 토목분야에서 구조부재의 매력적인 대체부재로 고려될 수 있다. 그러나 펄트루젼 FRP는 탄성계수가 상대적으로 낮고, 부재의 단면이 복부와 플렌지 등의 얇은 판요소로 구성되어 있기 때문에 압축재로 설계할 때 구조적인 안정성은 매우 중요한 고려사항이 된다. 따라서, 압축을 받는 구조용 부재의 설계를 위해, 판요소의 좌굴 및 후좌굴강도를 고려해야 한다. AISC/LRFD의 강구조 설계기준에서는, 후좌굴강도에 추가적인 단면 내 일정하지 않은 응력분포의 영향을 형상계수(form factor)를 사용하여 고려하고 있다. 이 논문에서는 압축력을 받는 펄트루젼 FRP 구조용 부재의 형상계수를 해석적으로 연구하였으며, 형상계수를 설정하는 과정에 대하여 제안하였다.

• 소음진동
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• 제10권6호
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• pp.1067-1074
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• 2000

이 논문은 여러 개의 스프링으로 탄성지지된 기둥의 고유진동수와 좌굴하중에 산정에 관한 연구이다. 하나의 스프링을 폭이 매우 좁은 탄성지반으로 모형화하고, 이 모형을 이용하여 기둥의 자유진동과 좌굴된 기둥의 탄성곡선을 지배하는 미분방정식을 유도하였다. 이 미분방정식들을 Runge-Kutta법과 행열값 탐사법을 이용하여 미분방정식의 고유치 즉 고유진동수와 좌굴하중을 산정하였다. 수치해석 예에서는 고정-고정, 고정-회전, 회전-고정 및 회전-회전의 단부조건을 고려하였다. 수치해석의 결과로 기둥 변수들과 고유진동수 및 좌굴하중 사이의 관계를 고찰하고, 스프링으로 지지된 지지되지 않은 기둥의 진동형을 비교하였다.

• 한국공간구조학회논문집
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• 제12권2호
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• pp.89-98
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• 2012

본 연구는 공간 트러스의 전체 좌굴을 고려한 최적 구조설계에 대해 연구를 하였으며, 구조물의 최소중량을 구하는 것이 목적이다. 응력제약에 의한 부재 최적화를 위해서 수리 계획법이 사용되었으며, 뜀-좌굴을 고려하기 위해 동적 계획법을 적용하였다. 트러스 부재의 최적설계를 위한 수리 모형은 전체중량 목적함수와 인장 또는 압축 허용응력 및 세장비 제약식으로 구성하였다. 평형경로상의 임계점 즉 좌굴하중을 구하기 위해서 접선 강성행렬의 행렬식 변화를 조사하였으며, 설계하중에 대한 좌굴하중 비율이 동적계획법의 반복계산과정에서 공간 트러스의 강성을 조절하기위해 반영되었다. 제안된 최적설계 프로세서의 검증을 위해서 스타 돔 구조물 예제를 통해 조사하였으며, 수치 결과는 잘 수렴하고 모든 제약을 만족하였다. 제시된 최적설계 프로세스는 전체좌굴을 고려한 최적설계를 수행하기 위한 비교적 간단 방법이고, 실무 구조설계를 반영하는데 가능하다.

• 한국공간구조학회논문집
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• 제14권4호
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• pp.81-88
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• 2014

Construction of vinyl house structures is increasing because they do not have a large cross section as non-permanent structures. Vinyl house structures are apt to collapse by snow load because they have a small size member as a temporary building. Therefore, it is very important to ensure not only the stiffness of the individual member, but also the overall stability of three-dimensional arch-type vinyl house structures. The purpose of this study is to estimate the stability of arch-type vinyl house structures that have a various curvature under the vertical load such as snow load. As a result of the study, the buckling load of V27 model is the largest, and the values of buckling load have a tendency to increase with increasing H(height of arch) in the case of $H{\leq}2.75m$, but to decrease with increasing H in the case of $H{\geq}2.75m$.

• Steel and Composite Structures
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• 제18권6호
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• pp.1331-1351
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• 2015

Cold-formed built-up members are compression members that are common in multiple areas of steel construction, which include cold-formed steel joints and stud walls. These members are vulnerable to unique buckling behaviors; however, limited experimental research has been done in this area. Give this gap, experimental testing of 71 built-up members was conducted in this study. The variations of the test specimens include multiple lengths, intermediate welds, orientations, and thicknesses. The experimental testing was devised to observe the different buckling modes of the built-up C-channels and the effects of the geometrical properties; to check for applicability of multiple intermediate welding patterns; and to evaluate both the 2001 and 2007 editions of the American Iron and Steel Institute (AISI) Specification for built-up members in pure compression. The AISI-2001 and AISI-2007 were found to give inconsistent results that at times were un-conservative or overly conservative in terms of axial strength. It was also found that orientation of the member has an important impact on the maximum failure load on the member.