Cyclic behavior of a novel bolted beam-to-box column connection with reduced beam section

Abstract

The present research investigates the seismic performance of innovative subassemblages in built-up box columns with reduced beam sections (RBS) technique through the finite element (FE) analysis method. The configuration of the subassemblages additionally benefits from having an extended endplate connection, which allows the subassemblages to be erected quickly and at a lower cost. So far, there has been very little detailed research on RBS moment connections in box columns with extended bolted endplates due to the closed shape of box columns and difficulty of accessing the column inside for developing a reliable load path. To solve these complexities, a novel configuration called “Reduced Bolted Extended Endplate accompanied by Stub Beam (Reduced BEEP-SB)” is introduced. The new load transfer mechanism of the subassemblages is described. Furthermore, 35 various exterior beam-to-column subassemblages are modelled in ABAQUS/STANDARD FE analysis software and tested under the connection qualification cyclic loading conditions. The results indicate that the proposed subassemblages can push away plastic hinge formation at an appropriate distance from the column endplate interface. Also, the flexural capacity of subassemblages is approximately 10–20% higher than the beam plastic moment capacity. Moreover, the results in terms of moment-rotation curves and strain in critical sections show that the models without continuity plates could satisfy the connection qualification criteria. It is noteworthy that the accuracy of the introduced models was validated via two experimental models.