EXPERIMENTAL ANALYSIS AND FINITE ELEMENT DAMAGE MODELING OF CONCRETE-FILLED STRUCTURAL TUBES SUBJECTED TO PURE BENDING

This study explores experimental testing on eight square concrete-filled tubes (CFTs) with varying width-to-thickness ratios, subjected to both cyclic and constant displacement amplitude under pure bending conditions. Comprehensive finite element modeling (FEM) has been conducted by ABAQUS software to closely replicate the experimental outcomes, focusing particularly on low-cycle damage and failure modes. The simulations incorporated concrete crushing and steel ductile damage, applying an element deletion technique to emphasize material fracture. The FEM results showed strong alignment with the observed cyclic behaviour from the experiments, with an error in energy dissipation under 7%. Lastly, an analytical expression is provided to estimate ultimate parameters (displacement at failure) for FEM applications, offering an effective tool for simulating the hysteretic response of CFTs.