## 1 Introduction  
The primary function of fixed offshore platforms in the Gulf of Mexico is hydrocarbon extraction, producing approximately 1.718 million barrels of oil daily [1]. These production volumes position Mexico as a significant oil-producing country, with crude oil exports reaching 831 thousand barrels per day, valued at 1.715 billion dollars [2, 3]. Mexico faced a decline in oil production, which was halted in 2019. To counteract this trend, Pemex's General Strategy for Oil and Gas Exploration and Production established strategic objective 3.1, aimed at accelerating the development of newly discovered fields, with an expected liquid production of 554 thousand barrels per day. Additionally, objective 2.3 focused on enhancing the recovery of mature and new wells, targeting a total hydrocarbon production of 2.319 million barrels per day by 2027 [4]. Consequently, the need to install new drilling platforms in both existing and future fields has emerged. From a civil engineering perspective, designing and constructing structures that support exploration and production activities remains a critical challenge, balancing cost-effectiveness and safety. The analysis, design, and construction of offshore platforms demand specialized expertise due to their exposure to harsh marine environments. These structures must withstand extreme loads, including hurricanes with wave heights of up to 16 m, seismic events, drilling equipment loads exceeding 5000 tons, hydrostatic collapse due to pressure, and fatigue in tubular joints induced by wave action over time. Given the continued necessity for offshore installations in Mexico and globally, literature resources such as Ageing and Life Extension of Offshore Structures [5] provide valuable insights into structural durability and maintenance. Regarding the structural performance of tubular joints, various experimental studies have been conducted to assess their strength under different loading conditions. For instance, [PERSON] [6] examined the ultimate compressive strength of perforated offshore tubular members, demonstrating that resistance assessments remain consistent under different loading scenarios, while penetration capacity varies with applied loads. Experimental studies concluded that the high strength of core concrete is beneficial for the durability of thin-walled CFST stub columns [7]. Furthermore, fatigue analysis plays a crucial role in predicting the lifespan of tubular joints. Probabilistic methods have been implemented to optimize inspection planning for offshore structures, including fixed and floating platforms as well as jack-up drilling rigs [8]. Fatigue analysis, based on S-N curves, allows for the prediction of crack initiation and propagation. Notably, DNV GL has conducted a joint industry project to develop probabilistic methods for in-service inspection planning for fatigue cracks, the findings of which are now incorporated into recommended practices [9]. Additionally, extending the service life of existing platforms remains a growing challenge in the oil industry, necessitating advanced fatigue analysis models that incorporate precise corrosion parameters [10]. Fatigue behavior has also been extensively studied in various marine structures at different depths. Researchers have proposed models characterizing damage as either a Gaussian or narrow-band process, depending on the variable amplitude loading induced by waves [11]. Moreover, advanced 3D finite element (FE) fatigue analysis, based on constitutive equations and continuum damage mechanics, has been shown to be an effective tool for evaluating large and complex structures before installation, ensuring their safety and stability [12]. Elliptical surface cracks have been analyzed in finite elements [13]. Beyond offshore platforms, fatigue effects have been investigated in other steel structures, such as ship hulls and hydropower pipelines. Studies have explored ship service life extension strategies by assessing the structural condition and remaining design life [14].