Cyclic performance of double tee connections with short slotted holes

Abstract

A new type of double tee connection with short slotted holes in the T-stub stems is proposed in this study. Four full-scale double tee connection assemblies were tested under cyclic loading and the test results are compared with those of a control specimen with reduced beam section connection. The effects of slot length of the bolt holes on the failure mode, bearing capacity, ductility, energy dissipation of the connection, and the possibility of protecting the beam from being damaged under cyclic loading are studied. The test results demonstrate that this type of double tee connection shows excellent seismic performance as severe plastic deformation develops only in the T-stubs. The slippage of the bolts in the slotted holes can greatly increase the rotation capacity, ductility and energy dissipation of the connection to resist severe earthquakes. Furthermore, the small movement allowed for the beam end can prevent or reduce the risk of local damage progression in the beam flanges and web, which can increase the post-earthquake reparability of steel structures with such connections.