Experimental study on damage detectable brace-type shear fuses

Abstract This paper proposes new brace-type shear fuses (BSFs) in series connection. The BSF consists of 2 perforated flat plates, 2 middle bridging plates and 2 side bridging plates and it is designed to dissipate seismic input energy efficiently via shear and bending of its steel strips. The BSF combines the advantages of buckling-restrained braces and shear slit dampers as it merely needs a single brace for installation in a braced frame, and it is damage visible and detectable. Stiffness and strength of BSFs are uncoupled so that it can be designed with sufficient flexibility, and better ductility can be realized. Five specimens were designed with different lengths and widths for the steel strips. The proposed BSFs presented good energy dissipation capacity and ductility, and it was found that the length and width of steel strip have great effect on strength, stiffness, energy dissipation capacity and deformation capacity. Formulae to predict the initial stiffness, yield load and ultimate load of the BSF are proposed. A formula predicting the damage level of a building installed with BSFs is also proposed through residual plastic rotation angle of steel strips. A six-story BSF braced frame was studied numerically to examine the effect of BSFs on maximum and residual drift control. Finally, a step-by-step design procedure was proposed for BSF braced frames.