Investigation of Seismic Performance of (RBS) and Drilled Flange Connection (DFC) Containing rhombus Shaped Hole in Steel Moment Frames

ABSTRACT Objective Numerous studies have been conducted on steel connections like Reduced Beam Section (RBS) and Drilled Flange Connection (DFC). Each connection has advantages and disadvantages. The present study aimed to evaluate the effect of different connections on the behaviour of steel moment frames. Design/methodology/approach In this study, simple connections (No drilled on beam flange), Reduced Beam Section, drilled flange connection, and drilled connection with a variable diameter corresponding to the diamond-shaped hole (DFCV-a proposed model) were evaluated. The connection was modelled using the ABAQUS software, and then the moment-rotation graphs were extracted. Finally, Finite Elements Modelling was utilised to calculate the stiffness of each connection. A frame was modelled in SAP based on the stiffness calculated by Finite Elements Analysis in ABAQUS. Findings Based on the results, drilled connections with variable diameter, which are related to diamond-shaped hole, function and behave better than other drilled samples which were considered in this study. In this model, the hinge is formed in the middle of the holes. This model has the most rotational stiffness among all samples. In addition, formed hinges indicated that the connections and plastic hinge in the frames with simple and rigid connections are damaged more. Further, drilled connections caused less damage to the column. Research limitations/implications It is recommended to perform an experimental test to have a better understanding of the issue. Originality/value In this paper, the effect of beam drilling on moment frame behaviour factor was first evaluated by SAP software and indicated that diamond-shaped drilling has the best beam drilling arrangement results.