Researcher:	Therese Sheehan
Project duration:	2010-2013
Supervisor:	Dr Tak-Ming Chan
Funding body:	Corus Tubes and University of Warwick

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Background

Concrete-filled tubular columns hold many advantages in comparison with pure steel or reinforced concrete columns, particularly when used in seismic buildings. They are stiffer than hollow steel members, and easier to construct than regular reinforced concrete columns since formwork is not required. They also offer excellent ductility under cyclic loading due to the confinement of the concrete core. However, their advantages are not fully exploited in the current design guidelines, which recent research projects have generally found to be conservative. The steel tube and concrete core exhibit a complex interaction under low-cycle loading. Several parameters influence the strength and behaviour of the member such as the cross-sectional slenderness and methods of load introduction. The degree of confinement provided and behaviour of the steel tube also vary depending on the shape of the tube, with circular tubes providing a higher degree of efficiency than rectangular, and hence a variety of steel tubular shapes are under consideration for this project.

Methodology

Therese’s research will involve both computational modelling and laboratory experiments. The behaviour of the specimens will be predicted numerically and then modelled in a finite element package such as ABAQUS. Once the modelling has been completed, the results will need to be compared with the numerical predictions and then validated by a series of tests in the structures laboratory of the University of Warwick.

Aims

The purpose of this project is to assess the efficiency of concrete-filled tubes under the combination of axial load and lateral cyclic load. Specific attention will be paid to evaluating the ductility and energy absorption capabilities of these when used as columns in seismic buildings.

References

Aly, T. and Thayalan, P. and Elchalakani, M. and Patnaikuni, I. (2009) Theoretical Study on Concrete-Filled Steel Tubes under Static and Variable Repeated Loadings. Science Direct.

BS EN 1998:1 (2004) Eurocode 8: Design of Structures for Earthquake Resistance – Part 1: General rules, seismic actions and rules for buildings, BSI.

Hu, H.T. and Huang, C.S. and Chen, Z.L. (2005) Finite Element Analysis of CFT Columns Subjected to an Axial Compressive Force and Bending Moment in Combination. Journal of Constructional Steel Research 61, Elsvier.

Susantha, K. and Ge, H. and Usami, T. (2001) Cyclic Analysis and Capacity Prediction of Concrete-Filled Steel Box Columns. Earthquake Engineering and Structural Dynamics, Wiley Science.

Zhang, Y. and Xu, C. and Lu, X. (2006) Experimental Study of Hysteretic Behaviour for Concrete-Filled Square Thin-Walled Steel Tubular Columns. Journal of Constructional Steel Research 63, Elsevier.