Cyclic hardening factor for replaceable shear fuse connections

Abstract Special moment frames (SMFs) with replaceable shear fuse (RSF) connections are being used as an alternative to SMFs that form beam plastic hinges. Capacity design of SMFs requires that the maximum moment that can develop at the column face be determined. Experimental work was performed to determine a cyclic hardening factor that can be used to calculate the maximum moment at the column face in SMFs with RSF connections. Five full-scale one-sided moment connections were tested to provide additional data. Data from these experiments were combined with data from previously-reported experiments to evaluate cyclic hardening. The combined data showed that cyclic hardening for RSF connections was greater than for traditional connections because the shear fuses do not experience local buckling. A cyclic hardening factor of 1.42 was shown to be reasonable for RSF design. In computing the maximum moment at the column face, the cyclic hardening factor should be applied to the fuse contribution but not to the elastic moments transmitted by the other connection plates.