Progressive collapse analysis of steel structures under fire conditions

Sun, Rui; Huang, Zhaohui; Burgess, Ian

doi:10.1016/j.engstruct.2011.10.009

Cited by 141 publications

(53 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Vulcan model combines alternate static and dynamic analyses [13], in order to use both to best advantage. Static analysis is used to follow the behaviour of the structure at changing temperature until instability happens; beyond this point an explicit dynamic procedure is activated to track the motion of the system until stability is regained.…”

Section: Analytical Implicationsmentioning

confidence: 99%

Connection behaviour and the robustness of steel-framed structures in fire

Burgess

2018

MATEC Web Conf.

View full text Add to dashboard Cite

Abstract. The full-scale fire tests at Cardington in the 1990s, and the collapse of at least one of the WTC buildings in 2001, illustrated that connections are potentially the most vulnerable parts of a structure in fire. Fracture of connections causes structural discontinuities and reduces the robustness provided by alternative load paths. An understanding of connection performance is essential to the assessment of structural robustness, and so to structural design against progressive collapse. The forces and deformations to which connectionscan be subjected during a fire differ significantly from those assumed in general design. The internal forces i generally start with moment and shear at ambient temperature, then superposing compression in the initial stages of a fire, which finally changes to catenary tension at high temperatures. If a connection does not have sufficient resistance or ductility to accommodate simultaneous large rotations and normal forces, then connections may fracture, leading to extensive damage or progressive collapse of the structure. Practical assessment of the robustness of steel connections in fire will inevitably rely largely on numerical modelling, but this is unlikely to include general-purpose finite element modelling, because of the complexity of such models. The most promising alternative is the component method, a practical approach which can be included within global three-dimensional frame analysis. The connection is represented by an assembly of individual components with known mechanical properties. Component characterization must include high-deflection elevated-temperature behaviour, and represent it up to fracture.In reality a connection may either be able to regain its stability after the initial fracture of one (or a few) components, or the first failure may trigger a cascade of failures of other components, leading to complete detachment of the supported member. Numerical modelling must be capable of predicting the sequence of failures of components, rather than considering the first loss of stability as signifying building failure. It is necessary to use a dynamic analysis, so that loss of stability and re-stabilization can be tracked, includingthe movements of disengaging members and the loadsharing mechanisms which maintain integrity and stability within the remaining structure, until total collapse occurs.

show abstract

Section: Analytical Implicationsmentioning

confidence: 99%

Connection behaviour and the robustness of steel-framed structures in fire

Burgess

2018

MATEC Web Conf.

View full text Add to dashboard Cite

show abstract

“…They stated that this difference in performance is due to the tensile membrane actions in the slabs and the robustness of structural steel joints. Sun et al (2012b) studied the progressive collapse mechanism of steel structures against fire loading. Their research demonstrated that as the beam section becomes larger and the load-ratio is lower in the unbraced structural frame, the global failure of entire building is arrested at higher temperatures.…”

Section: Latin American Journal Of Solids and Structures 12 (2015) 21mentioning

confidence: 99%

Fire response of a 3D multi-storey building with buckling restrained braces

Talebi

Tahir

Zahmatkesh

et al. 2015

Lat. Am. j. solids struct.

View full text Add to dashboard Cite

This paper investigates the performance of a three-dimensional multi-storey structure with Buckling Restrained Brace system (BRBs) under fire condition, using a sequentially coupled nonlinear thermal stress analysis. Efficiency of using BRBs in enhancing the strength and stiffness of a structural frame is compared with that of Ordinary Concentrically Bracing system (OCBs) under various fire scenarios. The proposed numerical model is verified by a series of full-scale fire tests carried out on an 8-storey structure at Cardington. The results indicate that the vertical movement of heated (buckled) column in the structural frame with BRBs is lesser than that with OCBs. Consequently, the tensile force and bending moment of the beam adjacent to the buckled column in the former is lesser than the latter. Also, BRB elements can perform better in redistributing the load sustained by heated columns without any buckling occurrence in the bracing member, in comparisons to the ordinary system. In general, it is observed that BRBs manifest an improved performance in re-stabilization of structural frame against fire for a longer period of heating time, such that a better fire resistance is offered to the whole building as compared to OCBs, due to a higher restraint provided onto the structure.

show abstract

“…An effective structural fire collapse analysis tool has been developed in the software Vulcan [10,11,12,13], with which the sequence of progressive failure within connections can be tracked during the course of a fire. The software is here utilized, firstly to validate the approximation of ductility demand from the simplified method, and secondly to perform the parametric study on the factors that affect it in fire.…”

Section: Limitationsmentioning

confidence: 99%