Experimental investigation of steel bolted T-Stub connections at different post-fire conditions

Abstract

The main factor in the collapse of steel structures is the bearing capacity of beam-column connections. One of the most common connection types for steel structures is the T stub connection. The bearing capacity of these connections is affected by loads such as earthquakes and fire. Therefore, in this study, the fire effect and the high-temperature value at the T connection were investigated to examine their effects on the behavior of the connection zone. The study was conducted using 15 T-Stub connections. T-Stub bolted joints examined in the study were produced using IPE standard profiles. Three cross-sections were used, with t_f/t_w ratios of 1.52, 1.56, and 1.58. The test elements formed using prestressed bolts of the same diameter were examined at four high temperatures. In the first part of the study, the behavior of 15 T-Stub connections under axial tensile loading was experimentally determined. The second part created a finite element model in ABAQUS for all models. The finite element model analysis results converged with those from the experimental study, with an average 2% error in maximum load-carrying capacity and 11% in energy dissipation capacity. As the t_f/t_w ratio increased, the F_max capacity increased, while the deformation capacity decreased. While no significant loss of cross-section stiffness was observed up to 600°C, significant stiffness loss was observed at 900°C.