Design and behavior of steel shear plates with openings as energy-dissipating fuses

Eleven steel shear plates with openings were tested to investigate their behavior under cyclic loading. Two types of steel shear plates were studied, the slit fuse with narrow slits that divide the plate into rectangular links, and the butterfly fuse with diamond shape openings that create butterfly-shape links in the plate. All tested fuses demonstrated fairly ductile behavior with full load – deformation hysteretic response at least up to 5% shear deformation, followed by pinched behavior, and eventually low-cycle fatigue induced fracture at a shear deformation of more than 20%, or 30% for the more ductile butterfly fuses. Fuses with partial or full buckling restraining device were also tested, which showed delayed buckling and earlier fracture compared to specimens without buckling restraining.

Design equations to determine the nominal strength and stiffness of the fuses are derived and examined by test results. A number of dimensionless parameters including the ratio of tangent stiffness to initial stiffness, residual bending strength to nominal strength, deformation at peak strength and ultimate deformation at fracture are established to develop the backbone curve for estimating fuse strength. Three dimensional numerical models of two butterfly fuse specimens were created and were able to simulate buckling and load – deformation response under cyclic loading with fairly good accuracy. More research topics are recommended for future studies.