Quelles sont les meilleures pratiques pour l’analyse structurelle des structures offshore ?

Los ingenieros offshore y los ingenieros estructurales deben diseñar, analizar y simular la respuesta de plataformas offshore o turbinas eólicas para una amplia gama de condiciones y capacidades de operación. Los diseñadores offshore utilizan software de análisis estructural offshore para resolver el diseño estructural de estructuras offshore, lo que incluye plataformas de petróleo y gas e instalaciones sobre la superficie del agua de FPSO y plataformas flotantes. Pueden analizar el ciclo de vida de diseño-operación-desguace. Los ingenieros offshore pueden crear diseños que soporten eventos accidentales, como cargas laterales incrementales por acciones sísmicas, impactos de embarcaciones, caída de objetos y carga de explosión.

Also key to note is mesh / node sizes depending on the software. You can have a finer mesh for critical structural joints/position where you expect higher loads/stresses. This will help to make more sense of the result.

Example: For a jacket-type offshore platform, it is important to use a detailed three-dimensional model that accurately represents the geometry of the structure, the material properties of the components, and the connections between them. Real story: A team of engineers was working on the structural design of a new jacket-type offshore platform. They used a simplified two-dimensional model for their initial analysis, but the results did not seem to be accurate. They then switched to a detailed three-dimensional model, and the results were much more realistic. This allowed them to make more informed design decisions and ensure that the platform would be safe and reliable.

Thorough Site Analysis: Understand seabed conditions and environmental factors. Accurate Load Calculations: Precisely calculate forces like waves and wind. Material Selection: Choose corrosion-resistant materials. Dynamic Analysis: Assess responses to waves using advanced simulations. Risk Assessment: Evaluate risks from extreme weather and seismic activity. Routine Inspections: Regularly inspect for fatigue and corrosion issues. Compliance: Adhere to industry standards and regulations. Advanced Modeling: Use sophisticated software for precise analysis. Monitoring Systems: Implement continuous structural health monitoring. Expert Teams: Engage experienced professionals for offshore structural analysis.

Selecting the right model for offshore structures is crucial for safety, efficiency, and cost-effectiveness. Accurate modeling ensures structures withstand environmental challenges, minimizing risks of accidents or failures. It optimizes design, materials, and construction methods, reducing costs and avoiding post-installation modifications. The right model aligns with industry standards, ensuring compliance and regulatory approval. It contributes to environmental sustainability by minimizing ecological impact and enhances operational efficiency throughout the structure's lifecycle. Ultimately, this meticulous choice safeguards investments and promotes responsible offshore development.

There are several methods of analyzing are 1. Thrust Line analysis, 2. Limit state analysis 3. Finite element analysis. Finite element analysis is able to determine the effects of load on the physical structures and their component under different condition and scenario.

Design rules to apply for the location of the plant in order to optimize the design. Any lessons learned fot the location from other previously build plants to be considered as well.

Example: When analyzing the structural response of an offshore platform to waves, it is important to use realistic wave data that takes into account the local wave climate and the operational conditions of the platform. Real story: A team of engineers was working on the reliability analysis of an offshore platform. They used a wave data set that was based on historical records from the area. However, the platform was designed to operate in deeper water than the historical data covered. They then used a wave model to generate a more realistic wave data set, and the results of their reliability analysis changed significantly. This allowed them to identify and address potential design weaknesses.

It is simply GIGO. It is good to understand the probability of occurrence for such loads as well to avoid over conservatism.

In offshore structural analysis, a meticulous site assessment is vital for accurate evaluations and risk mitigation. Precise load calculations, considering forces like waves and wind, maintain structural integrity. Opting for corrosion-resistant materials addresses marine challenges, ensuring durability. Dynamic analysis methods, including simulations, enhance understanding of structural responses to waves. Routine inspections swiftly identify fatigue and corrosion, sustaining structural health. Adherence to industry standards is imperative for safety, and advanced modeling tools provide precise analysis. Structural health monitoring offers real-time insights, and engaging expert teams ensures best practices in design and assessment.

Sensitivity analysis helps to make the design of the offshore structures more robust. Many of the loads experienced by offshore structures are not human controlled. Severity may increase overtime.

Identifying Influential Factors: Pinpointing key factors that significantly affect structural response and performance. Varying Parameters: Engineers can experiment with variations in material properties, geometric dimensions, boundary conditions, and load combinations. Assessing Structural Metrics: Evaluating changes in stress, displacement, natural frequency, and stability to understand the structure's behavior under different conditions. Optimization: Utilizing sensitivity analysis to optimize design by determining optimal values for input parameters, minimizing factors like cost, weight, or risk.

Example: Sensitivity analysis can be used to identify the key parameters that affect the structural response of an offshore structure. This can help engineers to focus their efforts on the most important parameters and make more informed design decisions. Real story: A team of engineers was working on the optimization of the design of an offshore platform. They performed a sensitivity analysis on the structural response to waves, and they found that the most important parameters were the wave height and the period. They then focused their optimization efforts on these parameters, and they were able to significantly reduce the weight of the platform without compromising its safety.

Sustainability: Include CFD as practise not as option. Fluid flowing in pipelines and all equipments has some kind of forces backfired over time. Hence, causing leakage, contamination or other structural defects being overlooked.

Example: Sensitivity analysis can be used to identify the key parameters that affect the structural response of an offshore structure. This can help engineers to focus their efforts on the most important parameters and make more informed design decisions

Example: Validation is the process of checking whether a model is accurate and consistent with known information. Verification is the process of checking whether a model produces correct results. Real story: A team of engineers was working on the verification of a finite element model for an offshore platform. They used a validation dataset that consisted of experimental data from a similar structure. They found that the model was able to reproduce the experimental data with good accuracy. This gave them confidence in the model and allowed them to use it for design purposes.

Very improtant. This is where the very basic principles of science (physics) comes in. More than the result of the FEA software, an offshore structures engineer must be able to explain the reason behind the results using first priciple.

In the realm of offshore structures, engineers deploy a toolkit of methods. Benchmark tests with standard problems set the stage, while cross-referencing results with different models or software adds layers of confidence. Quality checks and audits become our compass, and a critical review of assumptions and limitations keeps us on solid ground. These meticulous steps aren't just best practices; they're a commitment to precision. By embracing these methods, our engineers navigate the seas of structural analysis for offshore structures with assurance and efficiency.

The key to optimisation of offshore structures is driven by Topside Layout Design. The Topside Layout Design can be frozen only if process and safety studies are concluded and approved. Usually everywhere the focus is on offshore structures and jacket but without design freeze all optimisation efforts become futile. If the project has multiple platforms connected by bridges it becomes even more challenging.

The structural analysis of offshore structures involves complex considerations. Follow best practices to ensure safety and reliability. Conduct thorough environmental assessments to understand loading conditions. Utilize advanced analysis methods, such as finite element analysis, for accurate predictions. Consider dynamic effects like waves, wind, and earthquakes. Ensure materials and construction methods meet industry standards.

Layout is to drive everything , A good layout can save steel and better operation and maintenance ,access during operation in offshore facilities, multiple complex or stand alone platforms.

For design and analysis of offshore structures, following are some of the crucial data to be considered 1. Design life of operation 2. Geotechnical data 3. Metocean data 4. Modes of operation 5. Seismic data 6. Design fatigue life 7. T&I Engineering 8. Topsides required

Consider the effects of environmental factors such as wind, currents, and ice. Use appropriate design codes and standards. Involve experts in offshore structural analysis throughout the design process. Conduct thorough reviews of the analysis results.