Risk assessment of aging ship hull structures in the presence of corrosion and fatigue

An approach for risk assessment of the ultimate strength of an aging ship hull structure that is being degraded by corrosion and fatigue is developed. Time-dependent random function models for corrosion growth, fatigue cracks and corrosion-enhanced fatigue cracks that weaken the capacity of a ship hull are presented. The second-order reliability method is used to calculate instantaneous reliability of the primary hull structure. Methodology for computing the time-dependent reliability of a degrading aging ship structure is developed. Sensitivity of aging structure reliability to statistical and probabilistic description of corrosion and fatigue crack parameters is investigated. An example of a problem involving an aging tanker structure is used for demonstration.