• Title/Summary/Keyword: Structural collapse

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A Study on the Collapse Characteristics of Thin-walled Structural Members for Automobiles Under Axial Compression Load (차체구조용 박육부재의 압궤특성에 관한 연구)

  • 김정호;임성훈;양인영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.3
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    • pp.1-14
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    • 1997
  • In this paper, collapse test of thin-walled structural member widely used for automobiles is carried out under static compression load to observe the effects of cross- sectional shape and material on the energy absorbing capacity in the viewpoint of cras- hworthiness. Specimens tested consist of two sorts(Aluminium, CFRP) and configur- ations(Circular, Square) with variation in thickness. Also, comparisons of Al circular and square specimens are made to find the influence of difference in shape on the energy absorbing capability according as the thickness of specimen varies.

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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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Development of Linear Static Alternate Path Progressive Collapse Analysis Procedure Using a Nonlinear Static Analysis Procedure (비선형정적해석 절차를 이용한 선형정적 연쇄붕괴 대체경로 해석방법 개발)

  • Kim, Jin-Koo;Park, Sae-Ro-Mi;Seo, Young-Il
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.5
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    • pp.569-576
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    • 2011
  • In this paper a new analysis procedure for evaluation of progressive collapse resisting capacity of a structure was proposed based on the nonlinear static analysis procedure. The proposed procedure produces analysis results identical to those obtained by the linear static analysis procedure specified in the GSA guidelines without iteration, therefore saving a lot of computation time and excluding the possibility of human errors during the procedure. To verify the validity of the proposed procedure, the two methods were applied to the analysis of a reinforced concrete moment frame and a steel braced frame subjected to loss of a first story column and the results were compared. According to the analysis results, the two methods produce identical results in the prediction of progressive collapse and the hinge formation. As iterative analysis is not required in the proposed method, significant amount of analysis time is saved in the proposed analysis procedure.

No Collapse Design for Typical Bridges (일반교량의 붕괴방지설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.3
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    • pp.163-172
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    • 2014
  • The purpose of earthquake resistant design for typical bridges is the No Collapse Design and the Earthquake Resistant Design Part of Roadway Bridge Design Code provides a design process to construct the Ductile Failure Mechanism for the bridge structure. However, if it is not practical to provide the Ductile Failure Mechanism due to structure types or site conditions, the Brittle Failure Mechanism is an alternative way to get the No Collapse Design. As well as the existing design process constructing the Ductile Failure Mechanism, the Earthquake Resistant Design Part provides a ductility-based design process as an appendix, which is prepared for bridges with reinforced concrete piers. According to the new design process, designer determines a required response modification factor for substructure and transverse reinforcement for confinement therefrom. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected for which the existing as well as the ductility-based design processes are applied and different results from the two design processes are identified. Based on the results, an earthquake resistant design procedure is proposed in which designers should consider the two design processes.

Response Modification Factors and No Collapse Design of Typical Bridges (응답수정계수와 일반교량의 붕괴방지설계)

  • Kook, Seung-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.2
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    • pp.185-189
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    • 2017
  • The purpose of earthquake resistant design for typical bridges is the 'No Collapse Design' allowing emergency vehicles just after earthquakes. The Roadway Bridge Design Code provides design provisions to carry out such 'No Collapse Design' with a ductile mechanism and response modification factors given for connections and substructure play key role in this procedure. In case of response modification factors for substructure, the Roadway Bridge Design Code provides values considering ductility and redundancy. On the other hand, 'AASHTO LRFD Bridge Design Specifications' provides values considering additionally an artificial factor according to the bridge importance categories divided into critical, essential and others. In this study, a typical bridge with steel bearing connections and reinforced concrete piers is selected and different response modification factors for substructure are applied with design conditions given in the Roadway Bridge Design Code. Based on the comparison study of the design results, supplementary measures are suggested required by applying different response modification factors for substructure.

Numerical Simulation on Disproportionate Collapse of the Tall Glulam Building under Fire Conditions

  • Zhao, Xuan;Zhang, Binsheng;Kilpatrick, Tony;Sanderson, Iain
    • International Journal of High-Rise Buildings
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    • v.10 no.4
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    • pp.311-321
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    • 2021
  • Perception of the public to structural fires is very important because there are only a number of tall timber buildings constructed in the world. People are hesitating to accept tall timber buildings, so it is essential to ensure the first generation of tall timber buildings to a very high standard, especially fire safety. Right now, there are no specific design standards or regulations for fire design of tall timber buildings in Europe. Even though heavy timber members have better fire resistance than steel components, many conditions still need to be verified before considering the use of timber materials, e.g. fire spread, post-fire collapse, etc. This research numerically explores the structural behaviours of a tall Glulam building when one of its internal Glulam (Glued laminated timber) columns fails after sustaining a full 120-min standard fire and is removed from the established finite element building model created in SAP2000. The numerical results demonstrate that the failure and removal of the selected internal Glulam column may lead to the local failure of the adjacent CLT (Cross laminated timber) floor slabs, but will not lead to large disproportionate damage and collapse of the whole building. Here, the building is assumed to be located in Glasgow, Scotland, UK.

Optimal Seismic Design Method Based on Genetic Algorithms to Induce a Beam-Hinge Mechanism in Reinforced Concrete Moment Frames (철근콘크리트 모멘트골조의 보-힌지 붕괴모드를 유도하는 유전자알고리즘 기반 최적내진설계기법)

  • Se-Woon Choi
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.36 no.6
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    • pp.399-405
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    • 2023
  • This study presents an optimal seismic design method based on genetic algorithms to induce beam-hinge collapse mechanisms in reinforced concrete moment frames. Two objective functions are used. The first minimizes the cost of the structure and the second maximizes the energy dissipation capacity of the structure. Constraints include strength conditions of columns and beams, minimum conditions for column-to-beam flexural strength ratio, and conditions for preventing plastic hinge occurrence of columns. Linear static analysis is performed to evaluate the strength of members, whereas nonlinear static analysis is carried out to evaluate energy dissipation capacity and occurrence of plastic hinges. The proposed method was applied to a four-story example structure, and it was confirmed that solutions for inducing a beam-hinge collapse mechanism are obtained. The value of the column-beam flexural strength ratio of the obtained design was found to be larger than the value suggested by existing seismic codes. A more robust strategy is needed to induce a beam-hinge collapse mode.

Complete collapse test of reinforced concrete columns

  • Abdullah, Abdullah;Takiguchi, Katsuki
    • Structural Engineering and Mechanics
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    • v.12 no.2
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    • pp.157-168
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    • 2001
  • In this paper, experimental investigation into the behavior of reinforced concrete (RC) columns tested under large lateral displacement with four different types of loading arrangements is presented. Each loading arrangement has a different system for controlling the consistency of the loading condition. One of the loading arrangements used three units of link mechanism to control the parallelism of the top and bottom stub of column during testing, and the remaining employed eight hydraulic jacks for the same purpose. The loading systems condition used in this investigation were similar to the actual case in a moment-resisting frame where the tested column was displaced in a double curvature. Ten model column specimens, divided into four series were prepared. Two columns were tested monotonically until collapse, and unless failure took place at an earlier stage of loading, the remaining eight columns were tested under cyclic loading. Test results indicated that the proposed system to keep the top and bottom stubs parallel during testing performed well.

Simplified Collapse Analysis of Ship Transverse Structures (선체 횡구조물의 단순화된 최종 강도 해석)

  • P.D.C.,Yang
    • Bulletin of the Society of Naval Architects of Korea
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    • v.26 no.4
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    • pp.57-66
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    • 1989
  • In this paper, a theory for the static analysis of large plastic deformations of 3-dimensional frames, aiming at application to the collapse analysis of ship structures, is presented. In the frame analysis formulation, effects of shear deformations are included. A plastic hinge is inserted into the field of a beam end, and post. failure deformation of the plastic hinge is characterized by finite rotations and extensions. In order to model deep web frames of ship's structures into a framed structures, collapse of thin-walled plate girders is investigated. The proposed analysis method is applied to several ship structural models in the references.

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A numerical method for the limit analysis of masonry structures

  • Degl'Innocenti, Silvia;Padovani, Cristina
    • Structural Engineering and Mechanics
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    • v.18 no.1
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    • pp.1-20
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    • 2004
  • The paper presents a numerical method for the limit analysis of structures made of a rigid no-tension material. Firstly, we formulate the constrained minimum problem resulting from the application of the kinematic theorem, which characterizes the collapse multiplier as the minimum of all kinematically admissible multipliers. Subsequently, by using the finite element method, we derive the corresponding discrete minimum problem in which the objective function is linear and the inequality constraints are linear as well as quadratic. The method is then applied to some examples for which the collapse multiplier and a collapse mechanism are explicitly known. Lastly, the solution to the minimum problem calculated via numerical codes for quadratic programming problems, is compared to the exact solution.