Applicability of new regression model for determining axial load capacity of concrete filled double steel tubular composite columns

Using various composite materials and components as a replacement for conventional materials and components has various structural benefits in the construction field. Concrete Filled Double Steel Tubular Composite Columns (CFDST) are composite components consisting of two concentric metal (steel) tubes and a gap between them filled with concrete. These are composed of three constituent materials that exhibit higher structural performance than constituent materials. This study aims to propose a new regression model for determining the axial load capacity of CFDST columns. For this purpose, one twenty-four data collected from various experimental studies referred to literature. The model represented here was developed using the statistical tool Minitab. Length, yield strengths, diameters and thicknesses of both external and internal tubes of CFDST columns, compressive strength of in-filled concrete and experimental ultimate axial strength of CFDST columns are considered for model development. The model's applicability is confirmed when the developed model's results are compared to earlier researchers' models and the equations provided in the design guidelines. The suggested model achieves an R2 value close to one hundred percent and ultimate axial load capacity estimation with the least error. © 2022