Multilinear regression model for predicting the ultimate load of slender circular <scp>CFDST</scp> columns subjected to concentric and eccentric loading

Abstract This paper presents a novel approach to predict the ultimate load of slender circular concrete‐filled double skin tubular (CFDST) columns subjected to concentric and eccentric loading. The proposed approach was developed using a multilinear regression model through analyzing a database containing 165 CFDST column configurations. The data set was obtained by varying the magnitude of the parameters to determine its effect on the ultimate load using FE analysis. The variables considered in the model formulation are concrete strength, steel tube strengths, tube diameters, tube thicknesses, load eccentricity, column curvature, and column length. The accuracy and efficiency of the proposed models were validated with previous experimental investigations. The results demonstrate that the proposed models provide a practical, simple, and efficient approach to predict the ultimate load of slender circular CFDST columns subjected to concentric and eccentric loading. When compared to existing experimental work on slender circular CFDST columns subjected to concentric and eccentric loading, the proposed model over predicts the ultimate load by a maximum of 6%.