How Connections Affect Global Response

Recent research into the behaviour of steel connections in fire has focused on the testing of isolated connections with the aim of establishing moment-rotation-shear-axial behaviour. Experiments have typically been conducted on unprotected connections without an adjacent concrete slab. Numerical research, meanwhile, has focused on the characterisation of connection response given specific loading (thermal and mechanical) conditions. While these research areas are invaluable for structural understanding, it is important to consider how interaction with the surrounding structure can affect connection response.

In this paper, a numerical study has been conducted to examine the effect of connection type on structural response. The structure considered is a 16 bay single storey steel-concrete composite structure where one bay is subject to heating and then cooling during a parametric fire curve. The beam-to-beam and beam-to-column connections are varied from fully-fixed in rotation to partially-fixed to pinned. It is demonstrated that the magnitude of forces, deflections and rotations in the connections and beams are not significantly affected by the connection behaviour. However, the moments in the structural columns are found to be affected by varying the connection stiffness