The procedure of rationalization of Risk Ranking of Offshore Structures (Fixed and Floating structures) by applying Numerical Finite Element Analysis (FEA) in Qualitative and quantitative Structural Risk Assessments in SIMS (Structural Integrity of management systems) is evaluated in this paper. It is demonstrated by providing examples of how in philosophy based Risk Assessments, Advanced techniques like FEA can benefit traditional analysis. Subsequent impact of the outcome of Risk assessments can then be assessed.
Traditional structural risk assessment techniques (philosophy based) exclude the consideration of detailed and accurate FEA output such as component/principle stresses, crack growth rate, damage assessment, numericalstress concentration factors (SCF's), non-linear deformation characterization, complex geometries, etc. FEA inPhilosophy-based risk assessment provides realistic predictions of structural performance, strengtheningthe traditional techniques for cost effective and time consuming construction activities,which are used for life extension of brownfield structures.
The failure mechanisms modelled in FEA are fracture, cracking, fatigue, deformation and plastic collapse. The process involves data collection extracted from existing drawings, history, calculations, inspections, etc., followed by structural performance evaluation by developing 3D modeling and meshing structural elementsto perform FEA. The FEA outputis then used to produce a highly sophisticated and accurate analysiswhich is used to inform the strategy and program for improvement.
The Paper provides the background, procedure and benefits of using FEA outputs in risk assessment for Asset replacement plan, assurance and strategy. Structural parts of Assets integrity are discussed in this paper and so called SIMS. Asset replacement plan is followed by remnant life assessment (RLA) study includes the principal that seeking to fully make use of the existing offshore structures, latest methods for inspection, maintenance and remedial works, Identify the impacts of remedial projects in Capital and operating expenditure and link all existing Development, Engineering, Maintenance and Integrity studies and identify where additional studies are required.