Research On Whole Structure Strength Analysis And Internal Cargo Load Distribution Of Ultra Large Ore Carrier

With the recent rapid development of the world's shipping industry, the large-scale trend of ships is clearly accelerating. Since ultra large ore carrier (ULOC) has a huge loading capacity and China has become the world's largest iron ore consumer, ULOC has broad market prospects in the new era. Therefore, to realize the goal of China's shipbuilding industry–"Country builds its own ships to solute the country's energy problems", research and development of ultra large ore carrier has an important and realistic significance.There is a great difference in the structure like typical cross-section between ULOC and conventional bulk carriers and the large-scale requirements of the hull itself make the structure and properties of great concern. Because of its special structure and ultra large scale, conventional methods like beam theory in rules and cargo hold FEM can't be applied directly to correctly analyze the global hull strength of ULOC, so the whole ship finite element method is considered. Based on the study of whole ULOC analysis by FEM, the whole process including methods of setting up structural finite element model and mass model, wave load prediction, internal load calculation and technique of achieving inertia equilibrium for dynamic balance of whole ship loads is developed.For the simulation of ore load in the ULOC, this dissertation makes reference to the calculation model of earth pressure on retaining walls and uses the method of horizontal slices to analyze the pressure distribution of granular ore cargo on the bulkhead of the hold on the basis of the classical earth pressure theory. In comparison with the result of the liner distribution derived from the classical Coulomb's active earth pressure theory and common structural rules of bulk carriers, the pressure distribution from this paper shows evident non-linear characteristics and is consistent with the trend of actul ship mearsurements, especially on the lower end of the bulkhead close to the inner bottom where the pressure will be significantly smaller. Comparing the pressure distribution in different methods and comprehensively considering ore deposition and the movement of the ship in navigation like vibration and roll, a set of formula which is simple and relatively accurate was obtained and can be reference of internal ore load calculation for the strength check of ULOC.Taking a 450K deadweight ton ULOC as an example, the whole ship hull analysis is completed with the results of hull relative deformation and stress in different load cases. This paper can be guidance to carriers of this type on the whole ship analysis of structural strength by FEM.