Fracture Mechanics and Fatigue Analysis of Advanced Materials in the Oil, Gas, and Energy Industries

The oil, gas, and energy industries rely heavily on advanced metallic materials and structural components operating under extreme environmental and mechanical conditions. Steel catenary risers (SCRs), subsea pipelines, offshore platforms, and welded joints are critical elements exposed to cyclic loading, corrosive environments, and high-stress concentrations, making them susceptible to fatigue and fracture. This comprehensive review paper presents a detailed analysis of fracture mechanics and fatigue assessment methodologies applied to advanced materials in offshore and energy infrastructure. The study synthesizes findings from recent scientific literature, industry standards, and failure case studies to evaluate current practices in defect assessment, crack propagation modeling, and fatigue life prediction. Key standards such as BS ۷۹۱۰, DNV-RP-C۲۰۳, IIW-۲۲۵۹-۱۵, and API ۵۷۹-۱/ASME FFS-۱ are critically examined for their applicability in fitness-for-purpose (FFP) assessments. The role of welding residual stresses, variable-density flow dynamics, and mixed-mode loading in influencing fatigue performance is analyzed using finite element modeling (FEM), probabilistic approaches, and data-driven methodologies. Case studies from the Norwegian Continental Shelf and Brazilian offshore fields highlight recurring failure mechanisms and the importance of learning from historical incidents. Advanced modeling techniques such as the modified NASGRO equation, effective notch strain approach, and master S-N curve method are discussed in the context of low- and high-cycle fatigue regimes. The integration of digital twins, machine learning, and similitude-based failure assessment curves is explored as a pathway toward predictive maintenance and enhanced structural integrity management. This paper concludes with recommendations for improving design codes, incorporating real-time monitoring systems, and advancing multi-scale modeling frameworks to ensure the safety, reliability, and sustainability of energy infrastructure in harsh operating environments.

Keywords:

Fracture mechanics , fatigue analysis , steel catenary riser (SCR)