Analytical solution for local buckling strength of square CFT columns subjected to eccentric compression

Abstract

Theoretical study on local buckling behavior of square CFT columns subjected to eccentric compression has been carried out. Assuming that both the loaded edges and the unloaded edges of the steel plate are clamped, the analytical solution for local buckling strength of steel plates in square CFT columns subjected to eccentric compression is derived by energy method. Furthermore, the relationship between the local buckling coefficient of steel tube and the stress gradient is investigated. It is found that the local buckling coefficient of steel tube increases with the increase of the stress gradient. When the stress gradient equals 0, namely the steel plate is subjected axial compression, the minimum of the local buckling coefficient of steel tube is obtained, namely 10.312; when the stress gradient equals 2, namely the steel plate is subjected to pure bending, the maximum of the local buckling coefficient of steel tube is obtained, namely 22.713. Then, the relationship of local buckling strength of steel plates in square CFT columns subjected to eccentric compression with b / t ratios at different stress gradients is studied, resulting in the reasonable limitations for b / t ratios of the steel plates at different stress gradients in square CFT columns subjected to eccentric compression for the reference of engineering design.