【作者】 李丹丹；

【导师】 唐文勇； 蔡慧烈；

【作者基本信息】 上海交通大学 ， 船舶与海洋工程， 2008， 硕士

【摘要】 矿石专用船一般载重量较大,小于20万吨的为数不多。目前世界上在航的最大的矿石船是32万吨,由韩国大宇重工为德国船东建造,日本也建造了一些自用的矿石专用船,大多为25~26万载重吨。目前世界上还没有38万载重吨级的VLOC船投入营运,对其进行研究和开发,不仅可填补我国没有大型、巨型矿石专用船的空白,更重要的是为宝钢和长江沿岸的钢铁企业源源不断地输送原料,促进我国钢铁企业的持续发展。本文以目标船型38万吨巨型矿石船作为研究平台,以满足总纵强度、局部强度和屈曲强度要求为前提,对船体结构形式优化设计,同时对船体关键节点形式及其疲劳强度进行分析研究,主要包括结构形状和结构尺寸的优化,对VLOC的合理分舱、骨材间距的优化、纵骨类型(包括组合型材)的选取及高强度钢的使用研究,并对船体关键节点形式及其疲劳强度进行分析,以提供实际VLOC的设计作为参考。针对目标船,首先对船体结构形式进行优化设计,根据DNV规范,从纵骨间距、纵骨剖面的优化以及高强度钢的应用等几方面进行研究。然后进行舱段有限元的计算,其主要目的是找出承受较大动载荷的高应力区域,以及为精细网格的有限元计算提供边界条件。并对高应力区域及其连接结构,建立局部细化的有限元模型,从舱段有限元的相同的计算工况中选取边界条件,同时将载荷施加到精细网格的有限元模型上,进行分析。进行必要的疲劳强度以及疲劳寿命的校核。主要是从有限元模型的分析中得到各单元的应力进行处理,利用插值法得出危险点的应力值。然后根据节点的焊接情况,选取节点的焊缝系数。并根据选取部位的结构节点形式、受力特征和建造工艺,参考所选择的船级社规范选取S-N曲线,进行疲劳累积损伤度的计算。并基于该计算值对结构的疲劳寿命进行估算,以校核疲劳强度。同时,主要依据现有船型的相关资料,对典型节点提高疲劳强度以及疲劳寿命进行调研。更多还原

【Abstract】 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.更多还原