Improvement of Torsional Rigidity of Steel Supporting Structure Topside Module

The study investigates the improvement of torsional rigidity in floating support structures, focusing on the offshore industry’s structural integrity needs. Offshore platforms, such as Floating Production Storage and Offloading (FPSO) units, face challenges due to dynamic environmental loads and long-term corrosion effects, which compromise structural rigidity and stability. To address these issues, the research evaluates multiple factors affecting torsional rigidity, including bracing configurations, material selection, and cross-sectional dimensions of structural components. The study utilizes STAAD Pro software to analyze FPSO structures under various loading conditions, including wind, wave, and operational loads, to identify critical torsional responses. Various bracing configurations were tested, with a focus on knee bracing patterns, which showed significant potential in enhancing structural stiffness and minimizing torsional deformation. Empirical data demonstrated that knee bracing effectively improves torsional performance by reducing displacement and increasing modal frequencies across a range of section sizes. By optimizing the unbraced length ratio (a/L), the study highlights that larger sections with strategic bracing offer improved rigidity and vibration resistance, crucial for offshore stability under dynamic loading conditions. Recommendations from this research support industry-standard load combinations, providing a practical approach to enhancing torsional rigidity in floating offshore platforms. The findings contribute valuable insights into design optimization, promoting safer and more resilient offshore infrastructure. Major Findings: Knee bracing significantly improves torsional rigidity by reducing displacement and increasing modal frequencies. Improving torsional rigidity contribute to greater structural stiffness and vibration resistance, making structure more stable and resilient to dynamic environmental forces, particularly in harsh offshore conditions.