Concrete and Earthquake Engineering Research Group

Department of Civil & Structural Engineering

The role of connections in the response of steel frames to fire


Group members: 


Connections are critical structural elements of building frames, and in a fire are subject to forces very different from those at the ambient temperature for which they are designed. The fracture of a connection can cause the collapse of the connected beam, which may lead to a progressive collapse sequence affecting the entire building. This paper overviews the sequence of research on connection behaviour in a fire at the University of Sheffield. Early work focused on studying connections in terms of their moment-rotation behaviour alone. Concurrent full-scale building fire tests led to the realization that the tying capacity of connections is of prime importance for maintaining the structural stability in a fire. For wholestructure numerical modelling in performance-based fire engineering design, the development of the component-based approach, which was initially introduced for ambient temperature connection design, is an appropriate way to rationalize and model connection behaviour under these complex loadings. The effect of high co-existent rotation on the tying capacity of connections has been studied in furnace tests at various temperatures, which have provided data to assist in the characterization of the component-based model. A general component-based connection element, into which appropriate component models can be inserted, has been developed so that full connection performance, including fracture of components, can be integrated into global non-linear structural fire analysis. This will allow buildings to be modelled for a range of fire scenarios so that they can be designed to avoid progressive collapse in a fire.

Publication details

Publication type: 
Journal article
Awarded by: 
Journal / conference name: 
Structural Engineering International: Journal of the International Association for Bridge and Structural Engineering (IABSE)
Awarded date: 
Start page: 
End page: