The Assessment Of Fatigue Life Of Ship Structures

The analysis of accidents indicates that the fatigue is the main failure mode in ship structures.Generally, the simplified methods are employed in the engineering because the variable structure detailsand the different load conditions make this problem very complicated. The general principles of thefatigue life assessment of ship structures are reviewed. A program for calculating fatigue loads,stressesand cumulative damages as well as fatigue life based on DNV Classification Notes are compiled. As anexample, the fatigue life of the structure of an oil tank, VLCC(Very Large Crude Carrier), and acontainer ship (3800TEU) are analyzed by employing the software, and the program are proved to beeffective and reasonable. Furthermore, some fundamental principles of fatigue crack propagation infracture mechanics are reviewed. A preliminary way to evaluate the fatigue life of ship structures ispresented, and the fatigue life for typical structure details of a container ship are conducted.