Seismic performance of steel frame equipped with structural fuse

摘要

In the modern era of construction practices, there is a significant importance on the life safety of the structures. Seismicresilient steel frames are found to be more ductile, durable and dissipate the energy better. To make the frame resilient, theconnections are equipped with a structural fuse which safeguards the connection. After an earthquake, it is difficult to repairand replace the damaged connection components. To overcome this difficulty, the forces have to be mitigated to the nearbycomponent which is intended to fail. The component which is deliberated for failure near the connection is called a ‘Structuralfuse’. The concept of structural fuse is introduced in the semi-rigid beam-column connection to avoid the local failure of theconnection components and also enable unproblematic repair and rehabilitation. The objective of the research is to performa dynamic analysis on a steel frame equipped with an end plate connection and structural fuse. The shape of the fuse is ofvital importance, and fuse is modelled in the shape of an hourglass in the current research. The novel connection is fittedwith a steel portal frame, and its behaviour is assessed for P-δ effect and time history analysis. A novel connection has beenproposed 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 hourglassshape fuse and analysed for the inelastic drift capacity of the frame. Three different configurations of the frame, such asframe provided without fuse, single fuse and dual fuse, are considered. The frames are subjected to lateral cyclic load asper FEMA 350 (2000) loading history and assessed for P-δ effect and energy dissipation capacity. The time history analysishas been performed with the El Centro ground motion data of the first 5 s with a peak ground acceleration of 0.3 g. The keyfindings are hysteresis behaviour of the frame with fuse, energy dissipation capacity, base shear and top-storey displacementto assess the seismic capacity and critical assessment of failure regions. The ultimate load of the frame with single fuse is1.81, and dual fuse is 2.49% higher than that of the frame without fuse. The energy dissipation capacity of the frame withdual fuse is 44.51% higher than that of the frame without fuse. When the frame is fixed with a fuse, the base shear valueincreases substantially and the maximum lateral displacement is reduced. The research reveals that adding a fuse to the frameis a value-added component to mitigate the seismic force.