Authors: Research Scholar Venugopal Burugupally, Dr Ajay Swarup
Abstract: Concrete-filled steel tubular (CFST) sections are widely used in structural applications due to their superior mechanical properties, including high axial load capacity, energy dissipation, and fire resistance. This study presents a finite element analysis (FEA) of CFST columns under axial compression using ANSYS Workbench. The numerical model incorporates nonlinear material behavior, including an elastoplastic model with strain hardening for steel and the Drucker–Prager plasticity model for concrete to account for confinement effects. A structured finite element mesh was employed, with solid elements for concrete and shell elements for steel. The analysis considered realistic boundary conditions, applying displacement-controlled axial loading with fixed base constraints. The FEM results were validated against experimental data from the literature, showing a maximum deviation of less than 5% in peak axial load prediction. Load-displacement curves confirmed that steel confinement enhances concrete performance, delaying local buckling and increasing overall strength. Stress distribution analysis indicated effective load transfer between the steel tube and concrete core, while buckling patterns demonstrated progressive load redistribution, preventing sudden failure. These findings confirm that FEM is an effective tool for optimizing CFST designs and predicting their structural response under varying load conditions.
