Fatigue inspection and maintenance optimization: A comparison of information value, life cycle cost and reliability based approaches

Fatigue cracks increase structural failure risk and timely maintenance is very important. Maintenance planning often formulated as a probabilistic optimization problem, considering uncertainties in load modelling, material properties, damage measurements, etc. A decision rule or strategy, e.g. condition based (CBM), needs to be set up, then an optimal criterion threshold derived via solving the problem. This paper develops approach exploiting value of information (VoI) computation Bayesian optimization. The VoI explicitly quantifies added values from future inspections, gives (or strategy) by direct modelling alternatives evaluating their expected outcomes, rather than pre-defined strategy. comparative study on VoI, life cycle cost (LCC) reliability approaches conducted. It shown that takes all available strategies into account (both with without involving inspections), can reliably yield strategies, whether larger equal zero. When zero, LCC CBM lead suboptimal strategies. differences are illustrated fatigue-sensitive components marine structure.