Structure Strength Analysis For 38,0000 DWT VLOC

VLOC(Very Large Ore Carrier) usually has huge load capacity, which less than 200,000 dwt is very small. Now, all over the world, the biggest VLOC is 320,000 dwt, which is built at DAWOO shipyard for Germanic owner. Japanese shipyard also build some VLOC, most of them are among 250,000 ~260,000 dwt. Now there are no 380,000 dwt VLOC in service in the world. So the research can not only improve the experience for VLOC in China, but also keep supplying the materials for BAOSTEEL and other steelworks.The research is based on the 380,000t VLOC. This thesis tries to optimize the hull geometry and analyses some hot spot sections and fatigue strength, which should base on the sufficiency of longitudinal strength,local strength and buckling strength. That will be optimized the hull geometry,structure scantling,the cargo hold arrangement,longitudinal space and section and research for the high tensile steel's using. This thesis can give some reference for the design of VLOC.For the aimed vessel, first of all, optimize the hull geometry. The optimization is included the following factors: longitudinal space and sections,the use of high tensile steel, all of these are based on DNV rules. Secondly, a finite element (FEM) analysis of cargo hold is to be carried out, which can find out the high stress area, and gives the boundary condition for the refined FEM analysis. After added the loads, the refined finite element model can be used for analysis.Fatigue analysis may be carried out by methods based on fatigue tests (S-N data) and estimation of cumulative damage (Palmgrens-Miner rule). Where the loading or geometry is too complex, a finite element (FEM) analysis of the details is to be carried out to determine the hot spot fatigue stress. According to the character of the details and welded joint, one of the S-N curves and the stress concentration factors is to be used to calculate fatigue strength. Calculated fatigue lives, calibrated with the relevant fatigue damage data, may give the basis for the structure design of VLOC.Furthermore, base on the vessels which are in service, the method of improve fatigue strength and fatigue life for the typical details are carried out.