Liew and Xiong 2009
In this paper, a modified Eurocode approach is proposed to evaluate the preload effect on the axial resistance of CFT. The proposed approach is verified by experimental results and finite element analysis results. It is showed that the proposed method could give good estimation of the preload effect on the capacities of CFT.
Experimental Study, Results, and Discussion
A total of eight specimens were tested. The column specimens were fabricated from hot rolled circular steel tubes of 219 mm diameter and 6.3 mm thick. The steel tubes were preloaded by means of the pre-stressing strands anchored between the two end plates attached to the specimens. The pre-stressing strands were stressed to achieve the desired amount of preloads.
A modified column buckling formula is derived to consider the preload effect on the axial capacities of CFT. Predictions from the proposed formula are compared to test results and tests performed by other authors. The finite element package ABAQUS was adopted to perform finite element analysis. Theses comparisons demonstrate that the proposed formula can provide sufficient estimation of the preload effect. The preload effect is influenced by the preload ratios, slenderness ratios, and the cross-sectional configuration of the composite column such as relative wall thickness of steel tube, material strengths, etc.
Reference
Liew, J. Y. R., and Xiong, D. X. (2009). “Effect of preload on the axial capacity of concrete-filled composite columns.” Journal of Constructional Steel Research, 65(3), 709–722. doi:10.1016/j.jcsr.2008.03.023