Performance of ductile connections in 3-D composite frames under fire conditions

A novel axially and rotationally ductile connection has previously been proposed by the authors to prevent brittle failures of connections in fire. The study is now extended to investigation of the fire performance of the ductile connection in composite structures, particularly using a 3-dimensional model to consider the contribution of out-of-plane structural elements to the behaviour of the connection and the behaviour of the frame as a whole. In this paper, the design and the componentbased model of the ductile connection have been briefly introduced. A composite frame has been designed according to the typical frame used in the Cardington full-scale fire tests. Three 3- dimensional composite frame models with different types of connections have been built using the software Vulcan to compare the performance of the ductile connection in fire with ideally rigid and pinned connections. Finally, 2-D models have been built to simulate the central and edge secondary beams of the composite frame to make a comparison between 2-D modelling and 3-D modelling.