ABSTRACT
Service life extension programs for aging naval fleets typically involve engineering-based estimations of the current life expectancy of ships. In this article, we present a practical methodology we implemented to estimate the current life expectancy of the hull structure of an aging combatant ship. Such estimation was proposed to be derived from the accumulated fatigue damage in the ship structure due to wave-induced loads throughout its service life and strength-based criteria. Our assessment featured a rationally based identification and evaluation of critical ship structures against fatigue by performing Spectral Fatigue Analyses on three-dimensional global and local finite element models of the ship hull structure. Additionally, Extreme Load Analyses were carried out on the ship structure to account for its time-decreasing buckling and strength capabilities due to material degradation. As a result of such analyses, several structural components with presumed severe fatigue damage and reduced buckling and strength capabilities were identified.
