A Simplified Method for Determining the Bearing Capacity of Eccentrically Compressed Rectangular CFST Columns with Eccentricities in Two Planes

Nonlinear post-fire simulation of concentrically loaded rectangular thin-walled concrete-filled steel tubular short columns accounting for progressive local buckling

Numerical analysis of axially loaded rectangular concrete-filled steel tubular short columns at elevated temperatures

Local buckling of steel plates in concrete-filled steel tubular columns at elevated temperatures

Theoretical study on local buckling of rectangular CFT columns under eccentric compression

Computational simulation of elliptical concrete-filled steel tubular short columns including new confinement model

Round-ended rectangular concrete-filled steel tubular short columns: FE investigation under axial compression

Behaviour of eccentrically loaded high-strength rectangular concrete-filled steel tubular columns

Behaviour of rectangular concrete-filled steel tubular slender column with unequal wall thickness

Concrete-filled steel tubular (CFST) columns are widely used in engineering structures, and they have many different cross section types. Among these, normal solid sections and concrete-filled double-skin steel tubular sections are often used. Although many studies have been conducted on CFST columns with these two section types, no studies have been conducted on their damage assessment under blast loading. In this study, experimental analysis and a numerical simulation method were integrated to evaluate the responses and assess the damage of two concrete-filled steel tubular (CFST) columns with different cross sections subjected to near-field blast loading. The results showed that for a scaled distance of 0.14 m/kg1/3, plastic bending deformation occurred on the surfaces of the two CFST columns facing the explosive. The antiexplosion performance of the normal solid-section (NSS) CFST column was better than that of the concrete-filled double-skin steel tubular (CFDST) column. The explosion centre was set at the same height as the middle of column, and the distributions of the peak pressure values of the two columns were similar: the peak pressures at the middle points of the columns were the greatest, and the peak pressures at the bottom were higher than those at the top. With the analysis of the duration of the positive pressure, the damage at the middle was the most severe when subjected to blast loading. Using pressure-impulse damage theory and the validated numerical simulations, two pressure-impulse damage evaluation curves for NSS and CFDST columns were established separately by analysing the experimental and simulation data. Finally, based on the two pressure-impulse damage evaluation curves, the two pressure-impulse damage criteria for these two different fixed-end CFST columns were defined based on the deflection of the surfaces facing the explosives. Furthermore, the mathematical formulae for the two different column types were established to generate pressure-impulse diagrams. With the established formulae, the damage of the CFST columns with these two cross section types can be evaluated. Damage to other similar CFST columns with different cross section types due to near-field blast loading can also be evaluated by this method.

Effect of high-strength steel spirals on the seismic behavior of square concrete-filled steel tubular columns under high axial load ratio

Fiber element simulation of interaction behavior of local and global buckling in axially loaded rectangular concrete-filled steel tubular slender columns under fire exposure

This paper investigates the behaviour of concrete-filled steel tubular (CFST) columns and steel tubeconfined reinforced concrete (STCRC) columns when subjected to non-uniform fire conditions. CFST and STCRC columns exhibit enhanced sectional capacity compared to traditional reinforced concrete and demonstrate superior fire performance relative to steel columns. Because of their many advantages, CFST and STCRC columns are widely employed in the construction industry. However, limited research has been conducted on CFST columns and there is a notable absence of studies on STCRC columns exposed to non-uniform fire. Initially, finite element (FE) models of CFST columns and STCRC columns are developed for validation. To validate the models, a comparison of the results of FE models and tests is performed on the basis of temperature distribution, fire resistance and lateral displacement. A parametric analysis is then carried out to examine the impact of the various fire scenarios including 1-sided, 2-sided, 3-sided and 4-sided exposure on CFST and STCRC columns. Finally, the thermal-structural performance of the CFST and STCRC columns is compared. It is observed that the STCRC columns perform better than the CFST columns in nonuniform fire exposure. The observed comparisons and outcomes can help enhance the overall fire resilience of the buildings.

Local buckling of steel plates in rectangular CFT columns with binding bars

Comparative study on square and rectangular UHPFRC-Filled steel tubular (CFST) columns under axial compression

The effect of ribs and stiffeners on axial load carrying capacity on nineteen concrete-filled steel tubular (CFST) column models and the performance of three unstiffened square CFST columns and two octagonal CFST columns under seismic load by nonlinear static analysis using ANSYS Workbench 16.2 was numerically studied. The models used for this study are unstiffened square CFST columns, diagonal binding rib stiffened square CFST columns, longitudinally stiffened [1] square CFST columns [2], and unstiffened octagonal CFST columns. CFST column was validated against the experimental results under axial load [3]. An increase in thickness of steel tube, stiffener and rib show higher load-carrying capacity. Square CFST columns have more axial load carrying capacity than octagonal CFST columns. Stiffened CFST column has a higher load carrying capacity than unstiffened CFST column. The diagonal rib stiffened CFST columns having ribs with square openings had higher strength than those with circular openings. The ultimate strengths of the diagonal rib stiffened CFST column slightly decreased when the opening diameter in ribs increased and when the opening spacing increased. The unstiffened square CFST columns with thicker steel tubes performed better under seismic load than unstiffened octagonal CFST columns.KeywordsDiagonal binding ribsStiffenersCFST columnSeismicAxialLongitudinalOctagonalSquareCircularUltimate strength