Comprehensive FE Study of the Hysteretic Behavior of Steel–Concrete Composite and Noncomposite RWS Beam-to-Column Connections

Abstract

This paper investigates the behaviour of reduced web section (RWS) steel-concrete composite (SCC) beam-to-column connections with circular web openings through a comprehensive finite element (FE) analysis following experimental and computational studies.Results showed that the presence of a circular web opening is effective to move the plastic hinge away from the column shear panel zone and the main connection components, and hence, significantly improve the ductility and energy dissipation of the connection without critically affecting its capacity. The composite action was not considered in the literature to account for the severest case (slab acts as load only) in terms of load carrying capacity. However, this study proves that the composite effect has a decisive role in the calculation of the ductility and rotational capacity, and if not considered may result in an overestimated ductile behaviour. On the other hand, in cases where composite action is not provided depending on the particular flooring system, non-composite steel connections may be considered where the ductility and energy dissipation gains are definitely higher but the load carrying capacity is lower. This paper establishes the comparison between composite and non-composite connections and concludes that the contribution of the composite action to the load carrying capacity is higher with the increase of the beam web opening diameter. Therefore, the calculated negative load carrying capacity tends to be very conservative if the composite effect is neglected when a large opening diameter is used.

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

“…In models with high composite action, the difference was smaller than expected and previously observed in the study of Shaheen et. al [2] -for welded connections, being no higher than 2.8% in this study. This small reduction was attributed to firstly, Vierendeel mechanism, which led to symmetric behaviours in positive and negative directions.…”

“…However, the literature review revealed the lack of experimental and FE studies of steel-concrete composite RWS connections. The only one exists [2] showed that composite action should be considered and confirmed the contribution of composite action in the overall strength capacity of the connection as well as its effect on the RWS connection. Consequently, the aim of this paper is to develop a comprehensive parametric FE study to analyse the effect of the degree of composite action on the performance of steel-concrete composite bolted extended end-plate (BEEP) RWS connections subjected to cyclic loads with positive and negative bending moments.…”

Comparison of steel frames with RWS and WFP beam-to-column connections through seismic fragility analysis

“…When experiencing the DBE, FWFP can reduce the structural failure probability many times over, while FRWS has a higher risk of damage at LS1-LS3 than FWUF overall. However, it is worth noting that the calculated negative load carrying capacity of the RWS connection tends to be conservative when the steel-concrete composite effect is neglected (Shaheen et al, 2018). Perhaps in a steel-concrete composite structure, the premature damage to the RWS connections in the non-collapse stage will be improved.…”

A novel device to improve robustness of end plate beam-column connections

“…1, there are three common methods to improve the robustness of end plate steel connections [? ] by mobilising the plastic rotation from connection zone to a predefined location in the beam: strengthening the connection, reducing the beam section (RBS) and reducing the web section (RWS) [7]. These methods can be applied for retrofitting connections as well as in the design of new structures.…”