Predicting axial load capacity of CFST columns using machine learning

Abstract Owing to their economic and structural advantages, concrete‐filled steel tubular (CFST) columns have been implemented in diverse structural applications, especially in high‐rise buildings, suspension bridges, and subway stations. However, there is no agreement between international standards regarding the ultimate compressive strength of CFST columns subjected to concentric axial force or combination of bending moment and axial force, especially for slender sections and high‐strength materials. Considering such limitations, a comprehensive dataset on rectangular and circular (built up and hot rolled) CFST sections with different slenderness ratios was collected. The compiled experimental results were compared with corresponding values calculated by pertinent design code provisions, including AISC 360‐16 and Eurocode 4. The accuracy of design codes in predicting the axial capacity of CFST sections under concentric and eccentric loading was assessed accordingly. The distribution of the experimental‐to‐predicted data confirmed that the prediction error was dependent on the slenderness ratio of columns. However, the effects of other parameters, including the mechanical properties of materials and eccentricity level on the model error, were negligible. In the second phase of the study, a surrogate Machine‐Learning (ML) model was developed to estimate the axial capacity of circular and rectangular CFST columns under centric or eccentric loading condition. The accuracy of the proposed ML predictive model was appraised using several statistical metrics. The novel informational model attained superior accuracy and could be used to simplify generative design in future computational intelligence structural design platforms.