A numerical study on the structural performance of a ductile connection under fire conditions

Abstract

AbstractThe component‐based model of a novel ductile connection has been incorporated into the software Vulcan in order to facilitate global frame analysis within a performance‐based structural fire engineering design process. This paper reports on the validation and verification of the model, as well as the applications of the model in order to investigate the effects of the ductile connections on the structural responses of long‐span frames at high temperature. Firstly, three single‐beam models with the novel connections at both ends, connected to rigid supports, are used to verify that the component‐based connection model has been correctly incorporated into Vulcan, via comparisons against detailed finite element modelling with Abaqus. The structural performance in fire of long‐span frames with the novel ductile connections has been compared with the performance of the same frames with idealized rigid, idealized pinned and conventional end‐plate connections, initially using a limited sub‐frame model. Results show that, compared with the above mentioned three connection types, the ductile connection provides much higher axial and rotational ductilities to accommodate the deformations generated by the connected beams as their temperatures rise. As part of this process, these connections are instrumental in greatly reducing the axial forces to which the surrounding structure is subjected. Finally, parametric studies varying several key parameters have been carried out, in order to optimize the design of the ductile connection to enhance its performance subject to catenary action at very high temperature to prevent potential connection fracture and progressive collapse.