HYSTERETIC PERFORMANCE OF WEAK-AXIS CONNECTION WITH I-SHAPED PLATES IN STEEL FRAME

Abstract

This paper elucidates numerically the behavior of weak-axis moment connections proposed by welding I-shaped plates in the H-section column to increase connection strength and ductility in steel frame. After validating the numerical methods through comparing the results of numerical analysis and experiments, the effectiveness of the proposed weak-axis connection were examined through comparing to the traditional weak-axis connection. The proposed weak-axis connection could move the highest stresses away from the start-stop points of a weld, and thus preventing the premature brittle fracture of the beam flange welds. The plastic hinge formed away from the beam-column interface, while the local buckling occurred in the weld access holes region in the traditional weak-axis connection. The proposed weak-axis connections can be classified as rigid in a strong-bracing system, and be classified as semi-rigid in weak-supported or unsupported system. And then a series of parametric studies was conducted to better understand the behavior of proposed weak-axis moment connections. The force-displacement relationships, location of the plastic hinge, Mises index (MI), triaxiality index (TI) and rupture index (RI) distributions at the beam flange welds were reported in detail. According to the numerical analysis, the design variables of I-shaped plates and widened flange plate are suggested, along with a design procedure.