Bearing Capacity of Multi-Cell L-Shaped CFST Columns Under Compression and Bending

In order to develop unified calculation methods for the bearing capacities of multi-cell L-shaped concrete-filled steel tubular （ML-CFST） columns under different loading conditions， a finite element analysis was conducted using ABAQUS. The effects of different parameters on the behavior of the ML-CFST columns were analyzed under uniaxial bending， bending at any angle， and eccentric compression. The study results demonstrated that the steel yield strength， steel tube thickness， and height of the web limb had a great influence on the flexural capacity. The flexural capacities <italic>M</italic>_0° and <italic>M</italic>_180° were found to be lower than those at other angles due to the minimal bending stiffness in these directions. The shape of the <italic>M_x</italic>₀/<italic>M</italic>_π/4-<italic>M_y</italic>₀/<italic>M</italic>_3π/4 curve was similar to an ellipse. The steel yield strength and concrete compressive strength had a minor influence on the curve shape. The normalized interaction curve for biaxial eccentric compression expanded outward as the axial compression ratio increased. Based on theoretical and regression analyses of the numerical results， design methods for the bearing capacity of ML-CFST members under uniaxial bending， bending at any angle， and eccentric compression were proposed.