Experimental and numerical investigation of an innovative buckling-restrained fuse under cyclic loading

Structural fuses are sacrificial elements embedded in the structural members to localize potential failures within themselves. These replaceable segments are used to dissipate the energy of severe loads while preserving the integrity of the structure's major components. This paper presents an innovative Composite Buckling Restrained Fuse (CBRF) as a segment of a bracing element. CBRF with relatively small dimensions is a hysteretic damper with different performance in tension and compression. According to the typical difference of the bracing element capacities in tension and compression, the CBRF possess higher tensile strength than its compressive capacity. Utilizing tensile-only elements in this fuse with a new configuration improves the efficiency of the energy dissipation and eliminates the limitation of the tensile strength that exists in bracing members which contain ordinary ones. Key design parameters such as cross-sectional area and length of the fuse core are discussed theoretically. Six CBRF specimens with various dimensions and tensile-only elements were designed, tested and numerically modeled under cyclic loading to provide better insight into the fuse core and the encasing performance. The results indicated that the proposed structural fuse has a ductile behavior with maximum average core strain of 5.6% and sufficient tensile strength along with high energy absorption capacity.