Investigation of the Effect of Fire Loading on the Behavior of Connections with Beam-to-Column Bolted End Plate and T-Connection

In this study, comparison of the performance of beam-to-column bolted end plate connections and T-connection under fire is considered. To achieve this objective, samples are selected in three types of bolt number, the thickness of end-plate, and T-connection. Then, they are investigated and nonlinearly analyzed in ABAQUS finite element software and the results such as displacement-time curves, counters of stress and displacement are studied. According to the nonlinear finite element analyses results obtained in the first and second types, the beam-to-column connections have been investigated by changing the number of bolts and increasing the thickness of the end plate. The results indicated that the highest and lowest values of displacement-time curves are related to the samples have a 25 mm thickness end-plate with 4 bolts and a 10 mm thickness end-plate with 4 bolts, which affect the thickness of the end-plate with 36% and 17% fire resistance to rupture, respectively. It can also be seen that among the samples, connections with weak end-plates and fewer bolts in the final moment of loading at the end of fire analysis due to the high stress of plastic hinges can be seen. In the third type, the T-connection is examined with increasing thickness. The results showed that the maximum and minimum values of displacement-time curves are related to samples with a thickness of 17.5 mm and 9 mm with 25% and 11% fire resistance up to rupture, respectively. By comparison of the results of beam-to-column connection by changing the number of bolts and increasing the thickness of the end-plate and T-connection, the best sample has 25 mm thickness end plate with 8 bolts.