A Study of the Seismic Behavior of Special Steel Moment Resistancewith the Use ofDouble and Reverse Arc-Shaped Fuse on the Beam Flange

Unexpected brittle failure in steel rigid frameconnectionsby concentrated tensions on the welded area and connectionvulnerability in high ductility demands as occurred during the Northridge (1994) and Kobe (1995)has challenged ductility properties and ability to absorbseismic energy in this type of structural system. So in design of this type of structural system, creating ductility and ability to withstand cyclic large deformations is important. On this basis, in present study two new beam-to-column moment connections with reduced beam section by double orreverse arc-shaped fuseare studied in capacity design approach. The arc-shaped fuse, by removing flange and a part of web and replacing double orreverse arc-shapedin the section bending of the beam, resulted in a ductile fuse away from beam-to-column connections components, which prevents connection vulnerability in high ductility demands. The purpose has been numerically studied byfournumericalmodelsunder cyclic load using ABAQUS 6.10 finite element software. Obtained numerical results were compared with those of other studies. The numerical results show that arc-shapedfuse creates ductile fuses faraway from beam-to-column connectioncomponents and can satisfy acceptance conditions of special moment resistance connection based on AISC and FEMA. The arc-shaped fusecan increase drift story capacity up to 8% without any significant strength loss through increasing the out-of-plane stiffness of the beam longitudinal axis against lateral-torsional buckling.According toelasticflexural strengthandstiffnessof beam criteria,the reversearc-shaped fuseisabetter choicethan double arc-shaped fuse.