Fatigue design procedure for hull structures based on fracture mechanics

Sie sind hier: Homepage > Suche

Fatigue design procedure for hull structures based on fracture mechanics

Ushirokawa, O.

The fatigue fracture approach based on fracture mechanics is superior to the conventional one based on the material strength theory, because fracture mechanics can treat cracks simulating fatigue damage of actual structures. Although the fracture mechanics approach has already been applied to the design of structures such as LPG carriers, LNG carriers and pressure vessels, there have been only few applications of this approach to the structural design of general ships. In this study, using the approach based on fracture mechanics, fatigue fracture strengths of hull longitudinal members under fluctuating wave load are obtained. And fatigue strength safety factors for face plates, bracket toes of bottom girders and cross joints, which are elements of transverse strength members, are calculated and compared with conventional safety factors for these members. As a result of these analyses, it is clear that the fatigue strength of welded joints can be obtained by the analytical method based on fracture mechanics under certain assumptions, and this approach can rationally evaluate the differences between welded joint types or loading patterns. (Wassmann)