Simplified Method for Calculating the Bearing Capacity of Slender Concrete-Filled Steel Tubular Columns

Abstract

Concrete-filled steel tubular (CFST) columns are one of the most effective reinforced concrete structures, and improving their calculation is a critical task. The purpose of this study was to develop a simplified method for calculating slender CFST columns, taking into account the effect of lateral compression. The idea of the method is to use the equation of a reinforced concrete column’s longitudinal bending, without taking into account the effect of lateral compression. To take into account the lateral effects, the cross-sectional stiffnesses are corrected based on the analysis of the stress–strain state in the cross-sectional plane using the finite element method. The developed method was implemented by the authors in the MATLAB environment. The approbation of the proposed method was carried out on experimental data for centrally compressed columns of a circular cross-section, as well as eccentrically compressed columns of a circular and square cross-section, presented in two papers. For the centrally compressed columns, we conducted a study on the influence of initial imperfections in the form of eccentricities and initial curvatures on the value of the ultimate load. For the eccentrically compressed columns of the circular and square cross-section, the area of their effective operation was determined.

Artificial Neural Network Models for Determining the Load-Bearing Capacity of Eccentrically Compressed Short Concrete-Filled Steel Tubular Columns

“…In this work, when training artificial neural networks, the basis was a simplified model for determining the ultimate load, in which the stress diagrams in concrete and steel in the limit state were assumed to be rectangular, and the work of tensile concrete was not taken into account. The goal of our further research will be the development of artificial neural networks based on more complex models [61][62][63]. In this case, the nonlinearity of the diagrams of concrete and steel, as well as the dilatation effect, will be taken into account.…”

Two Stochastic Methods to Model Initial Geometrical Imperfections of Steel Frame Structures

“…However, a significant gap exists in detailed stochastic models for global imperfections in 3D frames. While probabilistic and reliability analyses often concentrate on individual components such as compressed columns [29,30] or bent beams [31,32], sensitivity analysis reveals that the load-carrying capacity of the frame is more affected by global imperfections than local ones [33]. The latest research involves the application of probabilistic methods to entire 3D frames, including sway imperfections [34].…”

Stability of Steel Columns with Concrete-Filled Thin-Walled Rectangular Profiles

“…At the present time, many numerical and experimental works (Alatshan et al [4], Chepurnenko et al [5], Grzeszykowski and Szmigiera [6], Florence and Senthil [7], Zhen et al [8]) are devoted to the topic of columns having hollow profiles filled with concrete. Storozhenko et al [9] performed experiments on high-strength composite columns subjected to eccentric loading.…”