Abstract:
The local structural forms of beam-column joints in steel structures have a notable effect on seismic behavior of steel frames. A new connection form adhering to the equal strength design criterion is presented in this paper, on the basis of researching the advantages and disadvantages of commonly structural forms of welded connections. A nonlinear finite model was developed using the finite element software ANSYS, considering both the local buckling and initial imperfection of the connection, and then its accuracy and applicability were validated according to existing experiments on steel frame welded joints. The seismic behavior of new-form joint was investigated in detail based on a comparative analysis between the new connection, the standard joint, the reinforced joint and the reduced beam section connection, including the following criteria: bearing capacity, fracture property, hysteretic behavior, degradation characteristics, failure mode, and accumulative damage. The analytical results show that the new proposed connection can move the plastic hinge outward from the joint zone without decreasing its stiffness. Moreover, it has a stable failure mode and hysteretic behavior and good performance in dealing with fracture and accumulated damage.