Cyclic behavior of bolted connections with different arrangement of bolts

During the 1994 Northridge earthquake, relatively poor performance of the bolted web-welded flange connections (BWWFs) was observed. Thereafter, various types of connections such as end plate and T-stub bolted connections were suggested to be used in moment resisting frames that are often used in industrial and tall buildings. In this paper, finite element simulation is used to study and compare the cyclic behavior of fourteen specimens of the mentioned connection type by changing the horizontal and vertical arrangement of bolts. The results show that the moment capacity and the initial rotational stiffness of T-stub bolted connections are higher than that of end plate bolted connections designed based on AISC considering the total energy dissipation of both groups to be approximately equal. It is also evident that the probability of failure mode change in T-stub connections is higher than that of end plate connections under cyclic loading due to the arrangement variation of bolts. Based on the results of this paper, end plate connections are suggested for conditions where the imperfection in construction is probable.

Research highlights
► Distancing the bolts from the beam flange decreases total energy dissipation.
► Distancing the bolts from the beam flange produces hysteresis loops with more pinching.
► The moment capacity of T-stub connection is higher than the end plate, designed for identical sections.
► The energy dissipation of T-stub and end plate connections is rather the same.
► The end plate connection is suggested for conditions where the imperfection in construction is probable.