Strength of Composite Columns Consists of Welded Double CF Sigma-Sections Filled with Concrete—An Experimental Study

Abstract

In-filled tubes section is a very successful configuration for axially loaded members such as columns and struts. Steel shell tube filled with concrete has many advantages, such as eliminating the need for shuttering, reinforcement bars or ties besides increasing both flexural and axial capacities and enhancing the ductility. The main disadvantage of in-filled tubes is the need for a shell thick enough to prevent the local buckling and hence the local decomposition. Previous studies tried to solve this problem using intermediate stiffeners or shear connectors. This research presents another approach to solve this problem using double cold-formed sigma-sections (face to face) as steel shell tubes. Sixteen specimens with different lengths, cross section dimensions and shell thicknesses were tested under both concentric and eccentric compression loads. Ultimate capacities, lateral deformations and normal strains were recorded. The theoretical capacities were calculated using AISC-LRDF-94, EN-1994-04 and CSI-COL software considering full composite action, and the deviations from the experimental results were 24%, 24% and 13%, respectively.

Estimating the Strength of Bi-Axially Loaded Track and Channel Cold Formed Composite Column using Different AI-Based Symbolic Regression Techniques

“…-Attach the column to the foundation or support using appropriate fasteners or anchor bolts [26]. -Ensure proper connections between the column and other structural elements, such as beams or floor systems [28]. (e) Quality Control and Inspection: -Regularly inspect the cold-formed columns during fabrication and installation to ensure compliance with design specifications and industry standards [28].…”

“…-Ensure proper connections between the column and other structural elements, such as beams or floor systems [28]. (e) Quality Control and Inspection: -Regularly inspect the cold-formed columns during fabrication and installation to ensure compliance with design specifications and industry standards [28]. -Conduct quality control checks for dimensions, tolerances, material properties, and welds (if applicable).…”

“…These loads can be obtained from structural calculations or analysis [31]. (d) Interaction Equations: -Use interaction equations, such as the Direct Strength Method (DSM) or the Effective Width Method (EWM), to evaluate the biaxial capacity of the column [28]. -The interaction equations consider the combined effects of axial compression and bending, accounting for the resistance of the column in both axes [30,32].…”

Experimental Study on the Impact of Using FRP Sheets on the Axial Compressive Performance of Short-Circular Composite Columns

“…f is the strength of a standard a b Equation (5) shows that for steel-concrete columns wrapped in FRP, if the circumferential confinement stress or the thickness of the confining circle of the outer steel pipe and FRP layer increases, the compressive strength of the composite column will be effectively improved accordingly.…”

“…Concrete-filled steel tube (CFST) columns are widely utilized in civil engineering structures due to their significant enhancement of the performance of inner concrete facilitated by steel tube confinement [1][2][3][4][5]. However, the outer steel tubes of these columns are susceptible to experiencing local buckling and erosion damage in service [6][7][8][9][10].…”