Study of Seismic Behavior of Drilled Flange Connection with Slot Hole

Document Type : Research Article


1 civil engineering AIU east tehran branch

2 Department of civil Engineering AIU East tehran branch tehran iran


Extensive damages in welded unreinforced flange (WUF) connections in 1994 Northridge earthquakes has led to the idea of using reduced beam section (RBS) connections and Drilled Flange (DF) connection to prevent brittle failure modes in welded joints. In this paper, the seismic behavior of DF moment-resisting connection with slot holes as an easy-to-construct method for DF connection in seismic regions was investigated. DF connection is made by drilling at top and bottom beam flange along beam main axis to establish an intentional weak point to reduce stress concentration at the beam to column flange welded connection. In this investigation, Finite Element models which were validated with previous experiments were utilized to consider the effect of slot holes in DF connection compared to circular holes on rupture potential of the beam to column welded connection. The utilized FE models of DF connection with various geometric properties and different panel zone strength ratios were developed to investigate the optimum slot hole configuration and reduce the rupture potential at CJP groove weld. The results showed that the optimum drilled slot holes can shift the plastic strain at the beam to column welded connection having the ratio of slot hole length to hole diameter (L/D) by up to 2. Using the configuration of the latter holes, the plastic strain at the beam to column weld connection and around the holes decreases approximately by up to, on average, 28 and 70% respectively compared to corresponding values of DF connection with circular holes.


Main Subjects

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