Fatigue Strength Evaluation Of A River And Sea-going Bulk Carrier

Fatigue is the main failure. Ship design companys are mainly based on cumulativefatigue damage (CFD) theory. However, there are many private ship design companyswhich did not know how to deal with fatigue. CFD theory does not include some importantfactors, for example loading sequence interaction, initial crack defect.More and more researchers came to study FCP.For the current situation, compare with CFD theory and FCP theory，the main worksof this thesis are as follows:(1) The fatigue strength assessment method and procedure based on S-N curve andCumulative Fatigue Damage theory for the Hull Structure Fatigue Strength assessmentwere introduced.(2) Combining the calculation methods for stress intensity factor of surface crack inweld structure and the unique crack growth rate curve method to calculate the fatigue lifeof ship structure were discussed.(3) The28000DWT river and sea-going bulk carrier was chosen as aim ship. Thestructure arrangement characteristic of bulk carrier is introduced, and ship structure fatiguehotspot part, hatchway corner weld seam and free boundary, is given based on generalstudy Hull Structure Fatigue Strength Manual of CCS.(4) The fatigue crack growth at weld toe and free boundary of the hatchway corner ofthe bulk carrier under random loading based on FCP theory were predicted.