• Title/Summary/Keyword: Progressive Collapse

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Simplified robustness assessment of steel framed structures under fire-induced column failure

  • Jiang, Binhui;Li, Guo-Qiang;Yam, Michael C.H.
    • Steel and Composite Structures
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    • v.35 no.2
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    • pp.199-213
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    • 2020
  • This paper proposes a Global-Local Analysis Method (GLAM) to assess the progressive collapse of steel framed structures under fire-induced column failure. GLAM obtains the overall structural response by combining dynamic analysis of the heated column (local) with static analysis of the overall structure (global). Test results of two steel frames which explicitly consider the dynamic effect during fire-induced column failure were employed to validate the proposed GLAM. Results show that GLAM gives reasonable predictions to the test frames in terms of both whether to collapse and the displacement verse temperature curves. Besides, several case studies of a two-dimensional (2D) steel frame and a three-dimensional (3D) steel frame with concrete slabs were conducted by using GLAM. Results show that GLAM gives the same collapse predictions to the studied cases with nonlinear dynamic analysis of the whole structure model. Compared with nonlinear dynamic analysis of the whole structure model, GLAM saves approximately 70% and 99% CPU time for the cases of 2D and 3D steel frame, respectively. Results also show that the load level of a structure has notable effects on the restraint condition of a heated column in the structure.

Evaluation of Post-Buckling Residual Strength of H-Section Steel Column for Both Ends are Fixed Condition (양단고정 단부구속에 따른 H 형 강재기둥의 좌굴 후 잔존내력 평가)

  • Abebe, Daniel Yeshewawork;Choi, Jae Hyouk;Kim, Jin Hyang
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.1
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    • pp.83-88
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    • 2013
  • Progressive collapse is a chain reaction of failures propagating throughout a portion of a structure that is disproportionate to the original local failure. When column members are subjected to unexpected load (compression load), they will buckle if the applied load is greater than the critical load that induces buckling. The post-buckling strength of the columns will decrease rapidly, but if there is enough residual strength, the members will absorb the potential energy generated by the impact load to prevent progressive collapse. Thus, it is necessary to identify the relationship of the load-deformation of a column member in the progressive collapse of a structure up to final collapse. In this study, we carried out nonlinear FEM analysis and based on deflection theory, we investigated the load-deformation relationship of H-section steel columns when both ends were fixed.

Dynamic Response of Reinforced Concrete Beams Following Instantaneous Removal of a Bearing Column

  • Tian, Ying;Su, Youpo
    • International Journal of Concrete Structures and Materials
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    • v.5 no.1
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    • pp.19-28
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    • 2011
  • This paper documents an experimental study of dynamic response of reinforced concrete beams following instantaneous removal of a bearing column. Four half-scale specimens representing two-span beam bridging across the removed column were tested. The test boundary conditions simulated rotational and longitudinal restraints imposed on a frame beam by the neighboring structural components. The gravity loads were simulated by attaching mass blocks on the beams at three locations. Dynamic loading effects due to sudden removal of a column were simulated by quickly releasing the supporting force at the middle of the specimens. The experimental study investigated the load-carrying capacity of beams restrained longitudinally at the boundaries and dynamic impact on forces. The tests confirmed the extra flexural strength provided by compressive arch action under dynamic loading. The tests also indicated that the dynamic amplification effects on forces were much lower than that assumed in the current design guideline for progressive collapse.

Equivalent Static Analysis of Progressive Collapse Using Equivalent Load for Stiffness (강성등가하중을 이용한 등가정적 연쇄붕괴 해석)

  • Hwang, Young-Chul;Kim, Gye-Joong;Kim, Chee-Kyeong
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2007.04a
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    • pp.375-380
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    • 2007
  • The goal of this paper is to develop a rational static method which consider efficiently the dynamic effect of the gravity load following sudden removal of element. For this goal this paper introduce the equivalent load for element stiffness which is a preceding research result and will develop equivalent static analysis which will be able to predict the maximum behavior considering dynamic effect. Some examples are provided to verify it. Equivalent static analysis is compared with the analysis method which is recommended by the GSA2003 guidelines and the time-history analysis which is the most accurate for dynamic behavior.

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