Cyclic Behavior of Axially Loaded Fuse Plates without Continuous Buckling Restraint

Modern building codes require structures in high seismic areas to resist earthquake forces through strength and ductility, yet inelastic deformation can render buildings unrepairable. One approach to mitigate unrepairable damage is the use of replaceable structural fuses. This paper explores the cyclic behavior of axially loaded fuses, focusing on two simplified fuse concepts: self-restrained (SR) fuses and fuses with discrete buckling restraint (BR) bolts. Ninety-four experiments were performed on reduced-scale fuse specimens with varying geometry. SR fuses with slenderness ratios near eight had the greatest deformation capacity under cyclic loading and similar cyclic tension and compression strengths. Better cyclic performance was achieved with relatively small fillets (half the fuse thickness). For the second type of simplified fuse, BR bolts were effective in delaying plate buckling such that low-cycle-fatigue occurred before strength loss from buckling. Fuses with finger-tight (FT) BR bolts were able to complete at least one additional cycle than fuses with snug-tight (ST) bolts when washers covered most of the width of the yield region. The experiments were complemented by finite element (FE) parametric studies.