PSI - Issue 70

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

356

4.2.2 Uniaxial Loading Under uniaxial loading, the stress distribution in the long column ranges from 25.7 MPa (compression) to 2.16 MPa (tension) as shows in figure 9, with the neutral axis remaining unstressed. Failure as shows in figure 10 occurs due to tensile cracking on one side and buckling on the other, particularly in slender columns where bending-induced instability is more pronounced. The load-displacement behavior a non-linear trend, with progressive yielding, and the maximum load recorded is approximately 65 kN, refl ecting the column’s response to bending under uniaxial loading. 4.2.3 Biaxial Loading Under biaxial loading as shows in figure 11, the long column experiences complex stress patterns, with the maximum stress reaching 31.59 MPa. The stress is most severe near the top section of the column, where the bending effects are maximized. Failure as shows in figure 12 under biaxial loading is primarily dominated by asymmetrical yielding and localized buckling, caused by significant stress interactions from two perpendicular bending moments. The load-displacement behavior are high non-linearity, with the maximum load recorded at 55 kN, indicating severe instability due to the biaxial moments. 5. Future Scope Future research should focus on experimental validation of the numerical results to ensure accuracy under real world conditions. Investigating CFST columns under dynamic, cyclic, and seismic loading will provide insights into their behaviour in extreme scenarios. Parametric studies varying material properties, tube thickness, slenderness, and loading angles can help optimize design. The application of high-performance materials such as fiber-reinforced or geopolymer concrete and advanced steel alloys holds potential to improve strength and durability. Additionally, exploring large-diameter and special-shaped CFST columns under complex loading remains a promising area. Life cycle assessments for sustainability and the development of comprehensive design guidelines based on combined experimental and numerical data are also key future directions. 6. Conclusion This study analyzed the structural performance of short and long CFST columns subjected to axial, uniaxial, and biaxial loading using Finite Element Analysis (FEA). The findings demonstrate that axial loading provides the most stable structural performance for both short and long columns, exhibiting linear stress distribution and high stiffness. The maximum applied loads for short and long columns under axial loading were 500 kN and 95 kN, respectively, with minimal displacement, indicating stable behavior under compression. Uniaxial loading resulted in bending, causing asymmetric stress distribution, with compression on one side and tension on the other. Failure occurred due to tensile cracking and buckling, especially in the slender long columns. The load-displacement curves showed a non linear trend with progressive yielding, with the maximum load recorded at 250 kN for short columns and 65 kN for long columns. Biaxial loading induced the most complex stress distribution, with higher stress concentrations at the edges, leading to significant instability. The failure modes were dominated by asymmetrical yielding and localized buckling, due to the combined effect of two perpendicular bending moments. The load-bearing capacity under biaxial loading was significantly reduced to 55 kN for the long column, indicating the severe effects of biaxial moments. Overall, short columns exhibited better performance under bending loads, while long columns were more susceptible to instability, particularly under biaxial loading. To improve structural stability, it is recommended to optimize material properties, increase reinforcement, and implement bracing systems for long columns. Future work should focus on experimental validation and advanced dynamic loading analysis for real-world applications. Acknowledgements The authors express their sincere gratitude to the SRM Research and Development Centre for providing the funding necessary to publish this work. The International Conference on Structural Integrity and Interactions of Materials in