Numerical study on prequalification and cyclic performance of column-tree connections

Abstract

Column-tree connections are commonly employed as a shop-welded and field bolted connection in the steel moment resisting frames to ease installation and inspection. The prequalification and cyclic performance of these connections are not completely clear yet. In the present study, using nonlinear finite element analysis by ABAQUS FEA software, the effects of bolted splice location and design method on the prequalification and cyclic behavior of the column-tree connection are investigated. The numerical models are validated based on experimental test results. The numerical analysis results show that the column-tree connection prequalification depends on the stub beam length and bolted splice design method; moreover, the bolted splice configuration influences the monotonic and cyclic behavior, strength, bolts pre-tension loss, stiffness, fracture tendency, ductility, and energy dissipation characteristics of the connection. Also, it is observed that based on the moment strength and rotational stiffness of the bolted splice, the column-tree connection is classified as a rigid or semi-rigid moment connection. This finding needs to be taken into account in the column-tree moment frame design.