Performance of steel beams with replaceable buckling restrained fuses under cyclic loading

Abstract

A new type of steel beam system with replaceable buckling restrained fuses was proposed. The replaceable fuse consists of flange connecting plates and web connecting plates as energy dissipation devices, and cover plates to prevent local buckling of the fuses. A total of seven specimens were tested to investigate the influence of cover plates and moment capacity ratio of fuses followed by a detailed finite element analysis to evaluate the performance of specimens at higher drift levels. The tests results showed that the specimens with buckling restrained fuses exhibited stable hysteretic behavior without experiencing strength degradation. Multi-wave buckling instead of first mode buckling was observed in the flanges connecting plates up to 4% drift. The seismic performance before and after the replacement of the damaged fuses was almost identical which indicated the seismic resilient ability of the proposed steel beam system. The strength and failure mode of the steel beam system was mainly controlled by the moment capacity ratio of fuses, and a limiting moment capacity ratio of 0.69 was recommended to remain the beam segments in elastic state with the maximum drift of 6%. Further, an idealized load-displacement relationship was established which can be adopted in the design of the proposed beams.