LNG船上层建筑整体吊装强度分析

发布时间：2018-07-09 20:59

本文选题：LNG + 上层建筑　；参考：《江苏科技大学》2015年硕士论文

【摘要】：随着船舶大型化的发展,上层建筑作为一个独立的分段,结构重量及外形尺寸都越来越大。为了适应高效造船的需求,上层建筑的预舾装率越来越高,吊装方式也从之前的分体吊装发展为如今的整体吊装。整体吊装作为一种更加高效的吊装方式,对上层建筑结构强度也提出了更高的要求。LNG船是国际公认的高技术、高难度、高附加值的“三高”产品,LNG船是在零下162摄氏度低温下运输液化气的专用船舶,是一种“海上超级冷冻车”,被喻为世界造船“皇冠上的明珠”。因此,相比于普通船舶,LNG船上层建筑对舾装率要求更高,在吊装过程中需要更严格地控制结构变形。本文以一艘大型LNG船上层建筑为研究对象,分析了在吊装方案设计、吊耳结构分析、吊装强度校核以及动载荷系数确定等几个过程中的的关键问题。为实际工程应用提供了理论依据,对上层建筑吊装有限元模拟具有很大参考价值。本文主要内容分为以下几点:(1)阐述了上层建筑整体吊装强度分析方法的发展历程,介绍了吊耳结构强度的分析方法。(2)介绍了普通吊耳的结构形式与规格,以及国内外企业的吊耳结构形式,分析了不同因素限制下整体多孔吊耳的结构响应特点。(3)利用有限元软件MSC.Patran建立了LNG上层建筑整体有限元模型,分析了上层建筑在起吊前以及平稳起吊过程中的结构应力与位移,确定了模型的高应力区域,对应力以及变形过大的区域进行了结构加强措施并通过计算验证了加强方案的可行性。(4)上层建筑吊装过程中动载荷系数的研究。利用MD/Nastran中瞬态响应分析功能,在四种不同吊机加速曲线下,对起吊瞬间上层建筑的运动形态进行了模拟,精确地得到了冲击载荷对上建结构的影响,通过结果的对比验证了现有动载荷系数的可靠性。
[Abstract]:With the development of large-scale ship, superstructure as an independent segment, the structure weight and shape size are increasing. In order to meet the demand of efficient shipbuilding, the pre-outfitting rate of superstructure is higher and higher. As a more efficient hoisting method, the integral hoisting has put forward higher requirements for the structural strength of superstructure. LNG carriers are internationally recognized as high technology and difficult. The high value-added "Sangao" product LNG carrier is a special vessel for transporting liquefied gas at minus 162 degrees Celsius. It is a kind of "marine super refrigerating vehicle", which is called the "pearl on the crown" of the world shipbuilding. Therefore, the outfitting rate of LNG ship superstructure is higher than that of ordinary ship, and the deformation of the structure should be controlled more strictly in the process of hoisting. Taking the superstructure of a large LNG carrier as the research object, this paper analyzes the key problems in the design of hoisting scheme, the analysis of hoisting structure, the checking of hoisting strength and the determination of dynamic load coefficient. It provides theoretical basis for practical engineering application and has great reference value for finite element simulation of superstructure hoisting. The main contents of this paper are as follows: (1) the development course of the analysis method of the integral lifting strength of superstructure is described, and the analysis method of the strength of the lifting lug structure is introduced. (2) the structural form and specifications of the ordinary hoisting lugs are introduced. The structural response characteristics of the whole porous hoist under different factors are analyzed. (3) the integral finite element model of LNG superstructure is established by using the finite element software MSC.Patran. The structural stress and displacement of superstructure before lifting and during stationary lifting are analyzed, and the high stress region of the model is determined. The structural strengthening measures are carried out for the areas with excessive stress and deformation and the feasibility of the strengthening scheme is verified by calculation. (4) the dynamic load coefficient in the process of superstructure hoisting is studied. Using the transient response analysis function in MD-Nastran, under four kinds of acceleration curves of crane, the motion pattern of superstructure in the moment of lifting is simulated, and the influence of impact load on the superstructure is obtained accurately. The reliability of the existing dynamic load coefficient is verified by comparing the results.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U674.133.3

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