Multi-scale numerical analysis of the eccentricity on the instability of RCFST long columns

Damage modes of the rectangle concrete-filled steel tube (RCFST) long columns under the eccentric compression were investigated by combining the finite element method (FEM) and the extended finite element method (XFEM) on the ABAQUS platform. The three-dimensional (3D) aggregates and the interfacial transition zone (ITZ) were generated at the middle height of RCFST. The parametric analyses were performed to test four RCFST long columns by varying the eccentricity ratio (γ). The results agreed well with the experimental results. The proposed multi-scale numerical simulation procedure can be used to understand the instability behavior of the RCFST long columns. [Display omitted] •Rectangle concrete-filled steel tube long columns have many instability modes.•Eccentricity ratio dominates concrete-filled steel tube long columns instability modes.•Python script process can set up a concrete-filled steel tube long columns multi-scale platform on ABAQUS.