Ductile connection to improve the fire performance of bare-steel and composite frames

Purpose In order to improve the robustness of bare-steel and composite structures in fire, a novel axially and rotationally ductile connection has been proposed in this paper. Design/methodology/approach The component-based models of the bare-steel ductile connection and composite ductile connection have been proposed and incorporated into the software Vulcan to facilitate global frame analysis for performance-based structural fire engineering design. These component-based models are validated against detailed Abaqus FE models and experiments. A series of 2-D bare-steel frame models and 3-D composite frame models with ductile connections, idealised rigid and pinned connections, have been created using Vulcan to compare the fire performance of ductile connection with other connection types in bare-steel and composite structures. Findings The comparison results show that the proposed ductile connection can provide excellent ductility to accommodate the axial deformation of connected beam under fire conditions, thus reducing the axial forces generated in the connection and potentially preventing the premature brittle failure of the connection. Originality/value Compared with conventional connection types, the proposed ductile connection exhibits considerable deformability, and can potentially enhance the robustness of structures in fire.