Performance assessment of damaged ship hulls

• A framework for performance assessment of ship hulls under sudden damage is presented.
• Various operational conditions (ship speed, heading angle, sea state) are investigated.
• Grounding and collision accidents are considered as sudden damage scenarios.
• Combined effects of sudden damage and progressive deterioration are investigated.
• The performance of ship hull is quantified in terms of ship reliability and robustness.

In this paper, a probabilistic framework for performance assessment of ship hulls under sudden damage accounting for different operational conditions is presented. Grounding and collision accidents are considered as sudden damage scenarios. The combined effects of sudden damage and progressive deterioration due to corrosion are investigated. The performance of ship hull is quantified in terms of ship reliability and robustness. The longitudinal bending moment failure is considered as the limit state. The longitudinal bending moment capacities of the intact and damaged ship hulls are assessed using an optimization-based version of incremental curvature method. The wave-induced loads for different ship speeds, headings and sea states are identified based on hydrodynamic analysis and the ship performance under different operational conditions is investigated. The approach is illustrated on an oil tanker. Under different operational conditions the reliability index associated with the intact and damaged ship hull and the robustness index associated with damage scenarios are presented in polar plots. In addition, aging effects on ship reliability are investigated.