Investigation of Effect of the Middle Link Beam Construction Imperfection on the Behavior of Connection in Steel Moment Frames

Geometric imperfections that occur due to the inevitable errors during the fabrication process or erection of structural members, may affect the performance of the steel structure. One of the most common and very efficient shop-welded and field bolted systems is the column-tree moment connection system. Sometimes, in the implementation of the moment-resisting frames with column-tree connections, the middle link beam length after the fabrication does not match with inserted dimension in shop drawing completely and a gap can be seen between the splice plates in beam to beam end-plate bolted splice connection, as shown in Fig. 1. The aim of this study is to investigate the effect of different values of the construction imperfections of the middle link beam length on the behavior of column-tree connections. For this purpose, firstly, the effect of the middle link beam construction imperfection in three steel moment-resisting frames with different stories and bays are considered by using SAP2000 software and the values of internal forces in members are extracted. Secondly, non-linear behavior of three-dimensional models of single-sided beam-to-column connection from these frames are investigated by using ANSYS Workbench finite element software.