Seismic performance of steel frame equipped with structural fuse

In the modern era of construction practices, there is a significant importance on the life safety of the structures. Seismic resilient steel frames are found to be more ductile, durable and dissipate the energy better. To make the frame resilient, the connections are equipped with a structural fuse which safeguards the connection. After an earthquake, it is difficult to repair and replace the damaged connection components. To overcome this difficulty, the forces have to be mitigated to the nearby component which is intended to fail. The component which is deliberated for failure near the connection is called a 'Structural fuse'. The concept of structural fuse is introduced in the semi-rigid beam-column connection to avoid the local failure of the connection components and also enable unproblematic repair and rehabilitation. The objective of the research is to perform a dynamic analysis on a steel frame equipped with an end plate connection and structural fuse. The shape of the fuse is of vital importance, and fuse is modelled in the shape of an hourglass in the current research. The novel connection is fitted with a steel portal frame, and its behaviour is assessed for P-delta effect and time history analysis. A novel connection has been proposed which consists of the main fuse, placed horizontally and a secondary fuse, placed vertically over the main fuse. This dual fuse arrangement is acted as a fuse and damper. A single-storey single-bay portal frame is fixed with an hourglass shape fuse and analysed for the inelastic drift capacity of the frame. Three different configurations of the frame, such as frame provided without fuse, single fuse and dual fuse, are considered. The frames are subjected to lateral cyclic load as per FEMA 350 (2000) loading history and assessed for P-delta effect and energy dissipation capacity. The time history analysis has been performed with the El Centro ground motion data of the first 5 s with a peak ground acceleration of 0.3 g. The key findings are hysteresis behaviour of the frame with fuse, energy dissipation capacity, base shear and top-storey displacement to assess the seismic capacity and critical assessment of failure regions. The ultimate load of the frame with single fuse is 1.81, and dual fuse is 2.49% higher than that of the frame without fuse. The energy dissipation capacity of the frame with dual fuse is 44.51% higher than that of the frame without fuse. When the frame is fixed with a fuse, the base shear value increases substantially and the maximum lateral displacement is reduced. The research reveals that adding a fuse to the frame is a value-added component to mitigate the seismic force.