Fatigue of Ship Critical Structural Details

During the past six years, a joint government-industry-sponsored project titled Ship Structural Maintenance Project (SMP) has been conducted at the University of California at Berkeley. As part of the SMP, fatigue of ship critical structural details (CSD) has been studied. This paper summarizes developments in the stress range—number of cycles to failure (SN ) analysis developed during the SMP. Nominal stress and hot spot stress procedures were employed to evaluate fatigue damage to ship CSD. A “cracked SN curve” approach was developed based on a hybrid SN -FM (fracture mechanics) methodology to evaluate the residual life of cracked ship CSD. The fatigue durability characteristics of repaired CSD was studied. Numerical examples are presented to illustrate these developments.