Abstract
In ship structures, fatigue cracks may initiate at the intersection between face plates of the longitudinals and web stiffeners attached to the transverse girders. These cracks may propagate in web plates of the longitudinals and may penetrate inner or outer skin plates, which have a possibility to cause the loss of oil and/or water tightness of critical compartment boundaries. Therefore, cracks must be detected by inspections before they reach the critical length. In the present paper, a simulation program is developed for multiple cracks propagating in a 3-dimensional stiffened panel structure. The simulation program can predict fatigue crack lives and paths taking into account the interaction of multiple cracks, load shedding during crack propagation and welding residual stress. The characteristics of fatigue crack propagations of ship structures are investigated by using the developed numerical simulation program and experiments. It is found that the crack propagation behavior in the ship structures may significantly change depending on the loading conditions, structural details and residual stress distributions.
