Fatigue Life Prediction of Ship Structure under Multi-axial Variable Amplitude Loads

초록

A longitudinal web frame of ship under multiaxial loads is selected to investigate the fatigue life. Also a model for this type of analysis is introduced. To confirm the results a commercial software named MSC/FATIGUE is applied. In the previous studies, the multiaxial loads have been classified into unaxial stresses to investigate the fatigure life. The total fatigue life was then derived from linera damage cumulative method. However, in the research a crack initiation and propagation theories of multiaxial are applied directly to fatigue investigation. From this new approach, the fatigue life under multiaxial loads can be explained more accurately. The results are compared with the ship strucrure fatigue strength assessment rule introduced by Korean Registre of Shipping which proved very good correlation.