The behaviour of steel and composite structures under a middle-column-removal scenario
Date of Issue2013
School of Civil and Environmental Engineering
NTU-MINDEF Protective Technology Research Centre
The objective of this research is to study the behaviour of steel and composite structures under a middle-column-removal scenario. Firstly, the behaviour of different types of steel bolted beam-column joints under a middle-column-removal scenario has been studied by experimental tests. A group of numerical models was developed and validated by the conducted experimental tests. As a result of the success of applying finite element analyses, parametric studies have been conducted using these numerical models to obtain the rotation capacities of various types of connections under catenary action. In addition, from the test results of the first series, it is found that bolted-angle connections normally performed better than other types of connections in the development of catenary action. In order to achieve a better understanding on the performance of bolted-angle connections under a middle-column-removal scenario, nine experimental tests were carried out on different types of bolted-angle beam-column joints. A new mechanical model has also been developed to predict the behaviour of bolted-angle connections under pure tension. This new mechanical model is proposed based on a series of component tests. In this model, the deformation capacities of bolted-angle connection components can be predicted. Based on this mechanical model, component-based models of bolted-angle connections have been proposed to represent the key responses of beam-column joints under a middle-column-removal scenario, including the formation of flexural action at small deformation stage, the development of catenary action at large deformation stage and fractures of the connection components at the last stage. Finally, a series of experimental tests was conducted in order to investigate the behaviour of composite beam-column joints under a middle-column-removal scenario and identify the contribution of composite slab to resist progressive collapse. The experimental tests consisted of two types of tests, namely, middle joints under sagging moment and side joints under hogging moment. A total of five composite beam-column joints with re-entrant steel profile decking were tested. The failure modes, the contribution of composite slab to resist progressive collapse and the key components which control the failure of the composite joints, were discussed in this study. In addition, a component-based model was developed to predict the responses of composite beam-column joints subjected to a middle-column-removal scenario.
DRNTU::Engineering::Civil engineering::Structures and design