• Title/Summary/Keyword: 좌굴성능

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Plastic Analysis of Steel Plate Shear Panels using Strip Model (스트립 모델을 이용한 강판 전단패널의 소성 해석)

  • Lee, Myung Ho;Moon, Tae Sup
    • Journal of Korean Society of Steel Construction
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    • v.18 no.1
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    • pp.71-80
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    • 2006
  • The behaviors of steel-plate shear panels were investigated through an experimental and analytical study, using mild steel (S40). Steel-plate shear panels buckle at small loads, and their strength is based on the shear panel's postbuckling strength due to tension field action. In design practice, however, the capacity of steel-plate shear panels is limited to the elastic buckling strength of shear panels. Th e National Standard on Limit States Design of Steel Structures, CAN/CSA-S16.1-94 (1994) contains a guideline for the analysis of thi n, unstiffened, steel-plate shear walls using the strip model. In this paper, the structural capacity of shear panels was evaluated using the results of the experiment and of the strip model analysis.

Inelastic Behavior and Seismic Retrofit of Inverted V Braced Steel Frames (역V형 철골 가새골조의 비탄성거동 및 내진성능향상 방안에 관한 연구)

  • Kim, Nam Hoon;Lee, Cheol Ho
    • Journal of Korean Society of Steel Construction
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    • v.15 no.5 s.66
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    • pp.571-578
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    • 2003
  • An effective seismic retrofit scheme for inverted V braced (or chevron type) steel frames was proposed by studying the redistribution of forces in the post-buckling range. The steel frames with chevron bracing are highly prone to soft story response once the compression brace buckles under earthquake loading. This paper shows that the seismic performance of such frames could be significantly improved by supplying tie bars to redistribute the inelastic deformation demand over the height of the building. A practical design method of the retrofit tie bars was also proposed by considering the sequence of buckling occurrence.

Study on Section Properties of Deckplates with Flat-Hat Stiffners (Flat-Hat 스티프너를 가진 데크플레이트의 단면 성능에 관한 연구)

  • Ju, Gi-Su;Park, Sung-Moo
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.1 s.11
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    • pp.77-86
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    • 2004
  • It is the buckling of the compression portions of the deckplate that govern its behaviour under wet concrete construction loading. The size and position of intermediate stiffeners in the compression flanges of thin-plate steel decks exert a strong influence on the dominant buckling mode of the flange. Test sections composed of high-strength steel were brake pressed with a variety of Flat-hat intermediate stiffeners in the compression flange forming a progression from small to large stiffeners. The ABAQUS program to determine the effectiveness of intermediate stiffeners in controlling buckling modes is undertaken. A series of specimens are loaded with simple beam. Various buckling wave forms prior to ultimate failure through a plastic collapse mechanism. The experimentally determined buckling stresses are found to be comparable with studies performed using the ABAQUS program analysis and using each country code.

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A Study about Behavior of Steel Column Members under Varying Axial Force (변동축력에 의한 철골기둥부재의 거동에 관한 연구)

  • Oh, Sang-Hoon;Oh, Young-Suk;Hong, Soon-Jo;Park, Hae-Yong
    • Journal of Korean Society of Steel Construction
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    • v.23 no.2
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    • pp.179-188
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    • 2011
  • The performance-based design is highlighted as an alternative for the current design method, which cannot definitely specify the performance level that a building requires. Research on it is already in progress, however, in developed countries like the United States and Japan, to establish the basis for a performance-based design. Many studies on such design are also being conducted in South Korea, but South Korea still lags behind other countries in all-around technology. On the other hand, the column members, especially the lower external column, are affected by the variation of the axial force by overturning the moments in the case of lateral loads by earthquake. Varying the axial force can affect the time of local buckling and the ultimate behavior. Thus, in this study, the structural performance, such as the time of local buckling and the ultimate behavior, was analyzed through an experimental study on column members under varying axial force. The feasibility of a domestic study proposing a performance level with a story drift angle formed about a structural-performance-based steel structure design was also verified.

A Study on Shear and Flexural Performance Evaluation of Circularly Corrugated Plate (원형 파형강판의 전단 및 휨 성능평가에 관한 연구 -전단 및 휨강도 설계식 제안-)

  • Moon, Seong Hwan;Oh, Sang Hoon
    • Journal of Korean Society of Steel Construction
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    • v.27 no.5
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    • pp.455-470
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    • 2015
  • This research suggest method to calculate more accurate shearing and bending force on corrugated steel plate that it is produced domestically. This research analyze limitation of former formula on domestic design standard and existing research. In addition The strength calculation formula on corrugated steel plate was proposed according to result of the experiment and FEM analysis. In this study, the result that compare experiment with analysis using the proposed shear buckling coefficient and limit width to thickness ratio indicate similar behavior. As the result of the research, It is judged that the structural member design and performance evaluation of the corrugated steel plate was conveniently applied.

Finite Element Analyses on Ultimate Compressive Strength of Longitudinally Stiffened Polygonal Sections (종방향 보강재로 보강된 다각형 단면 기둥구조의 극한강도 해석)

  • Choi, Byung Ho;Park, Seong Mi;Hwang, Min Oh
    • 한국방재학회:학술대회논문집
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    • 2011.02a
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    • pp.40-40
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    • 2011
  • 현재 일반적으로 활용되고 있는 원통형 쉘구조로 이루어진 타워구조의 대형화가 추진되면서 제작, 운반 편의성, 단면효율성, 경제성 제고를 위해 다각형단면 기둥구조물의 활용이 대두되고 있다. 하지만 다각형 단면 기둥구조의 극한강도에 대한 자료가 충분치 않고 관련 기준이나 지침이 명확히 제시되고 있지 않은 실정이다. 본 연구에서는 원통형 쉘구조물을 다각형구조물로 대체하여 제작될 경우 축방향 압축에 대한 내하력 향상 효과를 수치해석적으로 검토해 보고자 한다. 해석모델은 지름 2m, 두께 20mm인 원형강관 프로토타입 풍력타워 구조를 참고로 하여 이에 내접하도록 결정한 6~12각형 단면 형상으로써 높이 10,000mm인 3차원 기둥모델을 구현하였고 유한요소프로그램인 ABAQUS를 이용하여 해석하였다. 각 subpanel의 중앙에 종방향 보강재를 설치하였을 때 국부좌굴에 대한 내하력 변화를 비교하기 위해 종방향보강재로 보강한 모델을 구성하여 비교 해석을 수행하였다. 종방향 보강재의 제원은 미국 SSRC 제안식을 기준으로 삼았다. 탄성좌굴해석을 통해 탄성좌굴모드 형상을, 비선형비탄성해석을 통해 최종파괴모드 및 극한강도를 얻었다. 보강 전 후의 탄성좌굴 해석 결과로부터 최소모드의 고유치 값을 비교하였다. 각 subpanel 단면 중심부에 한 개의 보강재를 설치한 경우 탄성좌굴강도가 4배 가량 증가하였다. 이로부터, 보강재(n=1) 설치에 따라 유효 폭두께비가 1/2로 감소하는 효과를 확인 할 수 있다. 비선형해석결과로부터 subpanel의 단면중심에 보강재를 설치한 경우 보강재가 위치한 곳에 고정점이 형성되어 이를 중심으로 국부 좌굴모드에 변화가 생기는 것이 확인되었다. 이러한 변화는 다각형 단면 기둥구조의 내하력 성능, 즉 국부좌굴강도에 영향을 준다. 충분한 강성을 갖는 종방향 보강재가 설치된 경우, 극한상태에서도 유효폭두께비가 줄어드는 것과 같은 강도 향상 효과를 확인할 수 있다. 이러한 사실은 각 해석결과 극한강도를 DIN code, Migita와 Fukumoto의 제안식, SSRC 설계제안식 등과의 비교를 통해 확인할 수 있었다.

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Numerical Evaluation of Buckling Strength for High-Strength Corrugated Steel Structures (고강도 원형 지중강판 구조물의 좌굴성능에 대한 수치적 평가)

  • Choi, Dongho;Cho, Sunkyu;Park, Sangil;Moon, Eunkyung
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.6
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    • pp.75-88
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    • 2006
  • This paper evaluates the feasibility of use of high-strength steel for soil-metal corrugated steel structures. Two specifications, the AASHTO(2004) and the CHBDC(2000), were compared and the scientific background of equations for the buckling stability in those specifications were investigated to figure out the governing factors for buckling strength of structures. Numerous finite element analyses for round-pipe type of soil-metal corrugated steel structures were carried out with considering the elastic-plastic relationship of a material and the geometrical non-linearity, as well as the various design variables, such as span length, depths of soil cover, section properties, tensile strength and backfill conditions. Buckling strength equation of the CHBDC(2000) is still valid and conservative for both normal and high-strength steel soil-metal corrugated steel structures, and the buckling strength increases with the use of hight-strengths steel.

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Experimental Study on the Buckling Behavior of Cold-formed Steel Warren Truss (냉간성형강 평트러스 시스템의 좌굴 거동에 관한 실험 연구)

  • Park, Wan Soon;Kim, Gap Deuk
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.747-754
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    • 2002
  • Cold-formed steel truss system was reviewed in order to improve the various problems associated with the steel floor joist system, such as the structural deficiency caused by web punching and others. Two types of floor truss system using cold-formed steel were reviewed during this research project, including the square end type(SE type) and underslung type(EE type). The strctural behavior was analyzed using the AISI design criteria and various bending tests. Test results show that the SE type floor truss proved to be more efficient than the EE type when it is subjected to concentrated load, and that the unbraced length of the floor truss about the weak axis has much importance on the buckling strength of the floor truss. Test results indicate that their values surpass the calculated values predicated through the AISI design criteria.

Energy-Based Seismic Design of Buckling-Restrained Braced Frame Using Hysteretic Energy Spectrum (이력에너지 스펙트럼을 이용한 비좌굴 가새골조의 내진설계)

  • 최현훈;김진구
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.4
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    • pp.63-69
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    • 2003
  • In this study seismic design procedure for buckling-restrained braced frame systems was proposed using hysteretic energy spectrum and accumulated ductility spectrum constructed from single degree of freedom systems. The hysteretic energy spectra and accumulated ductility spectra corresponding to target ductility ratio were constructed first. The cross-sectional area of braces required to meet a given target displacement was obtained by equating the hysteretic energy demand to the accumulated plastic energy dissipated by braces. Twenty earthquake records were utilized to construct the spectra and to verify the validity of the design procedure. According to analysis results of three- and eight-story buckling-restrained braced frame structures designed using the proposed method, the mean values for the top story displacement correspond well with the given performance target displacements. Also, the inter-story drifts turned out to be relatively uniform over the structure height, which is desirable because uniform inter-story drifts indicate uniform damage distribution. Therefore if was concluded that the proposed energy-based method could be a reliable alternative to conventional strength-based design procedure for structures with buckling-restrained braces.