A connection element for modelling end-plate connections in fire

Abstract

In this paper a robust 2-noded connection element has been developed for modelling the bolted end-plate connection between steel beam and column at elevated temperatures. The connection element allows the element nodes to be placed at the reference plane with offset and the non-uniform temperature distributions within the connection. In this model the connection failure due to bending, axial tension, compression and vertical shear are considered. The influence of the axial tensile force of the connected beam on the connection is also taken into account. This model has the advantages of both the previous simple and component-based models. A total of 23 fire tests were used to extensively validate the model. It can be seen that the current model is robust and has a capability to predict the behaviour of bolted end-plate connection under fire attack with reasonable accuracy. Compared to the tested results the predictions of the current model were mainly on conservative side. Hence, the model can be used for structural fire engineering design on steel-framed composite buildings. The idea described in this paper can also easily be applied to develop other kind of connections, such as simple connection, column base connection or hollow section connection, and so on.

The effects of protected beams and their connections on the fire resistance of composite buildings

“…The proposed models are based on the two-node connection element framework developed by Huang [21]. In order to assess the influence of the axial ductility of connection on the connection's axial forces and deflection of the connected beam, five different levels of axial stiffness of connection were used to represent pinned and rigid connections for modelling of steel frame at elevated temperatures [21].…”

“…In order to assess the influence of the axial ductility of connection on the connection's axial forces and deflection of the connected beam, five different levels of axial stiffness of connection were used to represent pinned and rigid connections for modelling of steel frame at elevated temperatures [21]. The numerical analyses indicated that axial stiffness of the connection has a very limited influence on the deflection of the connected beam and negligible influence on the axial tensile forces of the connection [21]. Hence, in Huang's model the axial deformability of the connection is ignored.…”

Modelling partial end-plate connections under fire conditions

“…The main frame of Huang's 2-noded connection element [17] is extended here, to simulate the response of partial end-plate connections under fire conditions. In Huang's original model, the connection is specialized as a two-noded spring element which has no physical length (see Fig.…”

“…Huang [17] recently proposed a robust 2-noded connection element, for modelling flush and extended end-plate connection between steel beam and column under fire conditions. This model has good numerical stability under a static solver condition, and also retains the advantages of both the simple and component-based models.…”

Mechanical model and finite element analyses of the T-stub joint component in fire

“…Over the past decades, many researchers have adopted the component-based method to predict the moment-rotation (M-u) curves of the connection at elevated temperatures. Researchers, such as Da Silva et al (2001), Al-Jabri (2004), and Huang (2011), have developed component models to simulate the behavior of bare steel connections. A useful part of the component method is the concept of T-stub models, which have long been used to represent the behavior of each single bolt row.…”