Numerical Analysis of Concrete-Filled Steel Tubes Subjected to Axial Force

摘要

Proper material constitutive models for concrete-filledsteel tube (CFST) are proposed and verified by the nonlinear finiteelement program ABAQUS against experimental data. The crosssections of the CFST in the numerical analysis are categorized intothree groups, i.e., circular section, square section, and square sectionstrengthened by reinforcing ties. Via the numerical analyses, it hasbeen show that for circular CFST, the tubes can provide goodconfining effect to concrete especially when the diameter-to-tubethickness ratio is small. For square CFST, the tubes do not provide toomuch confining effect to concrete especially when the diameter-to-tubethickness ratio is large. The confining effect of square CFST withreinforcing ties is enhanced by the use of reinforcing ties especiallywhen the tie spacing is small and the tie number (or tie diameter) islarge.