High strength thin-walled rectangular concrete-filled steel tubular slender beam-columns, Part I: Modeling

High strength thin-walled rectangular concrete-filled steel tubular (CFST) slender beam-columns under eccentric loading may undergo local and overall buckling. The modeling of the interaction between local and overall buckling is highly complicated. There is relatively little numerical study on the interaction buckling of high strength thin-walled rectangular CFST slender beam-columns. This paper presents a new numerical model for simulating the nonlinear inelastic behavior of uniaxially loaded high strength thin-walled rectangular CFST slender beam-columns with local buckling effects. The cross-section strengths of CFST beam-columns are modeled using the fiber element method. The progressive local and post-local buckling of thin steel tube walls under stress gradients is simulated by gradually redistributing normal stresses within the steel tube walls. New efficient Muller's method algorithms are developed to iterate the neutral axis depth in the cross-sectional analysis and to adjust the curvature at the columns ends in the axial load–moment interaction strength analysis of a slender beam-column to satisfy equilibrium conditions. Analysis procedures for determining the load–deflection and axial load–moment interaction curves for high strength thin-walled rectangular CFST slender beam-columns incorporating progressive local bucking and initial geometric imperfections are presented. The new numerical model developed is shown to be efficient for predicting axial load–deflection and axial load–moment interaction curves for high strength thin-walled rectangular CFST slender beam-columns. The verification of the numerical model and parametric studies is given in a companion paper.

[1]  N. E. Shanmugam,et al.  Nonlinear Analysis of In-Filled Steel-Concrete Composite Columns , 2002 .

[2]  Brian Uy,et al.  Theoretical study on the post-local buckling of steel plates in concrete-filled box columns , 2000 .

[3]  Dennis Lam,et al.  Behaviour of normal and high strength concrete-filled compact steel tube circular stub columns , 2006 .

[4]  D. E. Muller.  A method for solving algebraic equations using an automatic computer , 1956 .

[5]  Qing Quan Liang.  High strength circular concrete-filled steel tubular slender beam–columns, Part I: Numerical analysis , 2011 .

[6]  Hanbin Ge,et al.  Strength of Concrete‐Filled Thin‐Walled Steel Box Columns: Experiment , 1992 .

[7]  R Q Bridge.  Concrete filled steel tubular columns , 1976 .

[8]  Brian Uy,et al.  Strength of slender concrete-filled steel box columns incorporating local buckling , 2002 .

[9]  Russell Q. Bridge,et al.  Behaviour of thin-walled steel box sections with or without internal restraint , 1998 .

[10]  Qing Quan Liang.  High strength circular concrete-filled steel tubular slender beam–columns, Part II: Fundamental behavior , 2011 .

[11]  Lin-Hai Han,et al.  Tests on Stub Columns of Concrete-filled RHS Sections , 2002 .

[12]  Brian Uy,et al.  Local buckling of steel plates in concrete-filled thin-walled steel tubular beam–columns , 2007 .

[13]  Qing Quan Liang.  Strength and ductility of high strength concrete-filled steel tubular beam-columns , 2009 .

[14]  J. Mander,et al.  Theoretical stress strain model for confined concrete , 1988 .

[15]  Tsong Yen,et al.  Experimental study on rectangular CFT columns with high-strength concrete , 2007 .

[16]  Qing Quan Liang,et al.  High strength thin-walled rectangular concrete-filled steel tubular slender beam-columns, Part II: Behavior , 2012 .

[17]  Brian Uy,et al.  Strength of concrete filled steel box columns incorporating local buckling , 2000 .

[18]  Dalin Liu.  Behaviour of eccentrically loaded high-strength rectangular concrete-filled steel tubular columns , 2006 .

[19]  Qing Quan Liang,et al.  Performance-based analysis of concrete-filled steel tubular beam–columns, Part I: Theory and algorithms , 2009 .

[20]  Stephen P. Schneider,et al.  Axially Loaded Concrete-Filled Steel Tubes , 1998 .

[21]  Kenji Sakino,et al.  ELASTO-PLASTIC BEHAVIOR OF CONCRETE FILLED SQUARE STEEL TUBULAR BEAM-COLUMNS , 1979 .