The Effect of Degree of Composite Action on Reduced Web Section (RWS) Connections

Due to the concerns regarding the effects of the composite action on the seismic performance of beam-to-column connections leading to premature brittle fracture of the beam bottom flange, this paper introduces a comprehensive finite element (FE) analysis studying the effect of the degree of composite action to the performance of the bolted extended end-plate (BEEP) RWS connections subjected to cyclic loads. Circular web openings with diameter equal to 0.8 of the beam's depth and two different parameters, namely the distance from the face of the column, S, and the degree of composite action, are investigated. Based on the results, it is confirmed that the degree of composite action of RWS connections is an important factor in seismic-resistant design. It is concluded that the low degree of composite action with the use of a structural fuse, such as an RWS connection with localised beam web opening, can potentially avoid bottom flange fracture damage. It is found that composite RWS connections can also be employed to improve the seismic performance on steel structures.