Beam-to-Gusset Plate Connection Using a New Method to Shift the Plastic Hinge to the Outside of the Connection

In special concentrically braced frames (SCBFs), beam-brace-column connections are fully rigid due to the presence of gusset plates and are the most important source for frame action. Research has shown that beams connected to the gusset plates may experience large rotation demands, local buckling and plastic hinge due to the frame action. The aim of this research is to prevent the plastic hinge and local buckling formation in the proximity of interfaces between beam and gusset plate and shift it to the outside of connection region. In the new proposed connection, beam-to-gusset plate interfaces are reinforced using a series of cover plates and stiffeners. In this study, eight SCBFs were considered and assigned into two groups including (1) SCBFs with conventional beam-to-gusset plate connection, and (2) SCBFs with proposed beam-to-gusset plate connection. These SCBFs were modeled in ABAQUS software under a cyclic lateral loading. The results showed that the hysteresis responses of SCBFs with the new proposed connection were similar to those of SCBFs with the conventional connection. Moreover, it was found that the proposed connection can shift the plastic hinge and the local buckling away from beam-to-gusset plate interfaces acceptably, preventing the large rotation demands in these regions.