study on the effect of the first hole distance of beam flange from column face on the seismic behavior of drilled flange connection (dfc)

beam to column welded connection with radius cut on beam flange is known as rigid connection that provides acceptable ductility for special moment resisting frame (smrf). in order to decrease the cost of construction and to provide an easy-to-construct structure, the new method is available for reducing the beam section based on drilling on beam flange , known as drilled flange connection (dfc). in this research, the effects of distance between first rows of holes from the column face on the seismic performance of dfc are studied for a specific configuration of the holes. based on the results, the above-mentioned distance should be limited to 0.45 to 0.7 of beam flange width to provide acceptable ductility for dfc.