Cyclic Behavior of Replaceable Shear Fuse Connections for Steel Moment Frames

Abstract

Most steel moment frames rely on beam yielding to safely handle the inelastic drifts that will be imposed by severe earthquakes. More resilient steel moment frame concepts such as post-tensioned self-centering frames and friction connections have not seen widespread use, perhaps because they deviate dramatically from current practice. Experimental work was performed to investigate the performance of a new moment frame connection called the replaceable shear fuse connection. The replaceable shear fuse connection uses beam flange plates with special cutouts to prevent beam damage. Seven reduced-scale specimens were tested to investigate the effect of fuse geometry on drift capacity, connection strength, and connection stiffness. The specimens achieved maximum drifts of 0.06–0.10 rad without experiencing strength degradation prior to fuse tearing. The shear fuses experienced strain hardening of 1.39–1.75 times yield, similar to high strain hardening that has been observed in shear link testing. The connections had more-than-adequate stiffness to be classified as fully rigid. Full-scale testing should be conducted to evaluate the effects of beam depth, column depth, and fuse parameters.