PSI - Issue 70

Siddharth Deswal et al. / Procedia Structural Integrity 70 (2025) 350–357

351

1. Introduction CFST columns have gained significant attention in modern structural design due to their excellent load-bearing capacity, durability, and cost-effectiveness. They are commonly used in high-rise buildings, bridges, and other civil engineering structures. However, the structural behavior of CFST columns under various loading conditions, particularly under uniaxial and biaxial bending, is complex and requires advanced numerical techniques for accurate assessment. This study aims to conduct a Finite Element Analysis (FEA) of CFST columns subjected to different loading scenarios (axial, uniaxial, and biaxial loading) to investigate their stress distribution, failure modes, and load displacement behavior. By comparing short and long column configurations, this paper provides valuable insights into the performance of CFST columns under axial and bending loads. 2. Literature Review Liu et al. (2020) Developed design procedures for special-shaped CFST columns using experimentally validated FE models, highlighting key parameters like steel-to-concrete ratio and column dimensions, and proposed simplified formulas for flexural resistance to aid practical design. Ma et al. 2021) Studied CECFST stub columns under eccentric compression through experiments and simulations, revealing that eccentricity strongly affects ductility and failure modes, and proposed improved design methods for accurate behaviour prediction. Analysed PEC columns with Fiber Reinforced Concrete (FRC), showing enhanced ductility, greater lateral displacement, and improved post-peak behaviou r, while highlighting FRC’s cost -effectiveness and design benefit Marinho et al. 2021. Zhong et al. (2021) Investigated HCFHST columns under combined loading, finding American standards accurate in predicting failure loads, while European and Australian codes overestimated them, emphasizing the need for precise design models. Fang and Visintin (2022) Explored GPCFST columns under various loads, showing high ductility and load capacity, while highlighting geopolymer concrete’s sustainability and CO₂ reduction potential in construction . Subedi et al. (2022) Examined axial compression in noncompact and slender CFSTs, finding concrete contributed over 60% to capacity under low confinement, and highlighted data gaps in large-diameter CFSTs and the need for research on combined loading. Fang et al. (2023) Studied seismic behaviour of CFCST columns using a finite element model, finding that higher steel ratios improved seismic performance but reduced ductility, and proposed simplified design equations for seismic loading. Li et al. (2023) Investigated slender TRC columns under eccentric loading, showing that concrete strength and high-strength rebar enhanced capacity and ductility, and proposed a new design method to improve performance. Shen et al. (2023) Studied ML-CFSTs under biaxial eccentric loading, finding that eccentricity and loading angles greatly impact capacity, and introduced a dimensionless interaction equation for predicting their behaviour under complex loads. Xu et al. (2023) Explored spiral-confined SCCFST columns under eccentric loading, showing that spiral confinement improved strength and ductility, with limited effect on capacity, and developed design expressions for axial and flexural capacity under eccentric loads. Yang et al. (2023) Investigated the seismic behaviour of hexagonal concrete-encased CFST columns, finding that outer reinforced concrete improved seismic resistance, and developed a finite element model to predict behaviour under various loads. Al-Rousan et al. (2024) Analysed CFST columns with GRAC infill, highlighting sustainability benefits, and proposed ACI code modifications to improve performance predictions, showing that increased steel tube thickness enhances capacity and ductility. Hassanein et al. (2024) Investigated CFDSCST columns under axial compression, finding that inner corrugated steel tubes offered better confinement and resistance, and developed a confinement-based design model for accurate axial resistance predictions. Examined SS-CFDST and SC-CFDST columns under axial compression, introducing a new design model based on lateral confinement pressure, validated through experiments and finite element modelling, showing that resistance was influenced by concrete strength and steel yield strength. He et al. (2024) Explored eccentric compression performance of short columns made from coral concrete and aluminium alloy, finding that higher concrete strength and aluminium content improved capacity, and proposed a correction coefficient model for better prediction. The research highlights the importance of tailoring design approaches to specific column types (e.g., special-shaped, slender, or geopolymer-filled) and loading conditions, while also addressing gaps in data for large-diameter CFSTs and complex loading scenarios. These discoveries give engineers useful resources for creating composite structures that are effective, long-lasting, and sustainable.