Cyclic performance of concrete-filled steel CHS columns under flexural loading

Based on the theoretical model, parametric analysis was performed on the behaviours of the moment (M) versus curvature (ϕ) response, and the lateral load (P) versus lateral displacement (Δ) relationship, as well as the ductility coefficient (μ) for the composite columns. Finally, simplified models for the moment (M) versus curvature (ϕ) response, and the lateral load (P) versus lateral displacement (Δ) relationship are suggested. A formula for the calculation of the ductility coefficient (μ) of the composite columns under constant axial load and cyclically increasing flexural loading is developed.