On inspection planning in the face of epistemic uncertainty in structural performance

The presence of epistemic uncertainties in probabilistic modeling of structural performance implies that not only one but a multitude of possible models should be considered. When such models are utilized in the context of reliability and risk analysis, this does not pose any particular problem. In fact, epistemic and aleatory uncertainties may be treated without differentiation. However, in the context of decision analysis, different outcomes of epistemic uncertainties are generally nonlinearly related to corresponding optimal decisions. This is particularly evident in risk- and reliability-informed inspection planning for dynamically sensitive structures, such as offshore wind turbine foundations. In the present contribution, we take up this challenge by explicitly accounting for the influence of multiple systems, i.e., different models associated with structural performance arising from epistemic uncertainty. To this end, we first propose to adapt and utilize a multi-system decision-making framework developed previously by the authors. Thereafter, we illustrate how this may be used in practice in the context of inspection planning of welded connections in offshore structures. We compare the results with traditional approaches and finally discuss the findings and implications.