For TotalEnergies Denmark, Matrisk, together with LIC Engineering, developed a probabilistic basis for assessing the fatigue safety and for risk-based inspection planning of an offshore platform as part of a digital twin study.

The aim of the project was to systematically quantify the uncertainty in the parameters of a digital structural model and to reliably estimate its influence on fatigue analyses and future inspection intervals. To this end, an existing structural model of the platform was compared with measurement data from operation to realistically depict the actual condition of the structure.

The focus was on Bayesian updating of the digital twin based on identified natural frequencies and mode shapes from acceleration measurements. The resulting uncertainties of the model parameters were then propagated through transient fatigue analyses and incorporated into risk-based inspection planning. This demonstrated how model uncertainties directly affect fatigue life, hotspots, and optimal inspection intervals.

The results provide a sound methodological basis for condition-based inspection strategies of offshore structures. At the same time, the project demonstrates how digital twins, measurement data, and probabilistic models can work together to plan inspections more effectively, make uncertainties transparent, and improve operational safety and efficiency.