Fatigue Life as a Variable in Assessing Naval Ship Flexibility

摘要

Recently established naval shipbuilding initiatives aim to grow national industry and facilitate ready technology insertion during different phases of the capability life cycle. In this landscape, combined with budgetary constraints and the complexities associated with ensuring the enduring capability of the fleet, a ship's structural performance is of importance. Ships should be sufficiently flexible to allow system upgrades and changes to operations. To assess the costs and benefits of options to meet evolving demands, it is critical to understand the contribution of a ship's structural performance to its capabilities. This is underscored by fatigue life prediction tools capable of linking structural parameters with other performance requirements. However, there is only a relatively small body of literature concerned with these elements. This paper presents a way to improve understanding of the uncertainties and interdependencies between the fatigue life and capability aspects of naval ships. Two case studies are presented: the first focuses on the effect of a potential technology upgrade on the fatigue life of two candidate ships for acquisition, the second on the effect of operational profile changes on the fatigue life of an in-service ship. The case studies evaluate the fatigue damage incurred at critical details of the different ships, which is significantly dependant on the operational profile and the added displacement due a technology upgrade. Finally, future work is discussed.