Behaviour of composite beam-column joints under a middle-column-removal scenario: Component-based modelling

In this paper, component-based models of composite beam-column joints under a middle-column-removal scenario have been proposed. Two types of connections, namely, composite web cleat and flush end plate connections, are analysed. Middle joints under sagging moment and side joints under hogging moment are both considered. Failure criteria are introduced for most connection components, which enable the component-based models to predict the failure of these two types of composite joints. In general, these component-based models give acceptable predictions of the composite beam-column joint behaviour under a middle-column-removal scenario. In addition, frame analyses were conducted incorporating the developed component-based models for the composite joints. The main objective of the frame analyses is to identify the differences in structural performance between an isolated joint and a frame model under a middle-column-removal scenario. Finally, parametric studies are carried out to investigate the effects of reinforcement ratios, profile decking and composite slabs on structural behaviour incorporating the composite joint model. Based on energy-based analysis, dynamic effect is also considered and dynamic load-carrying capacities of composite frames are obtained. It is also found from a parametric study that the beam span-to-depth ratio has a great influence on the frame behaviour under a middle-column-removal scenario.