| 摘要: |
| 以某薄膜型液化天然气（Liquefied Natural Gas，LNG）船的结构设计为例，开展全船屈服强度校核和基于精细网格的有限元疲劳强度分析。针对5种典型装载状态，基于美国船级社（American Bureau of Shipping，ABS）全船强度直接计算指南，采用ABS-DLA/SFA系列软件，用三维波浪载荷预报程序对波浪随机载荷进行长期预报。基于预报结果，针对每种装载状态计算15个设计波参数组，求解全船结构在各载荷组合工况下的应力分布，继而完成屈服强度校核。以甲板机械室与穹顶甲板相交处的关键节点区域的节点设计为例开展细网格局部强度分析，并通过各种改进设计解决应力集中问题。针对2种常用典型操作装载状态及营运于北大西洋海区疲劳寿命满足40a的要求，基于ABS全船疲劳强度直接计算指南计算2个典型细化位置热点应力传递函数，通过谱分析得到疲劳累积损伤和疲劳寿命，完成疲劳强度校核。采用的全船强度和疲劳分析方法和思路适用于其他超大型船舶的结构分析。 |
| 关键词: 大型LNG船 全船有限元强度分析 细化网格 疲劳分析 |
| DOI：DOI：10.14056/j.cnki.naoe.2017.02.001 |
| 分类号:U661.43；U674.13+3 |
| 基金项目:工信部“浮式液化天然气储存及再气化装置总体设计关键技术研究”（Z1214E01） |
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| Analysis on the Yield Strength and Structure Fatigue of a Membrane LNG Carrier with Global Finite Element Method |
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WANG Jia-ying
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（Hudong-Zhonghua Shipbuilding (Group) Co., Ltd.）
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| Abstract: |
| The global yield strength check and fatigue analysis based on finite element method (FEM) are carried out with refined mesh for the structural design of membrane LNG (Liquefied Natural Gas) carriers and the 3D wave loads prediction code of ABS-DLA/SFA series software is used to perform the long-term prediction of the random wave loads respectively under five typical loading conditions in accordance with ABS global FEM direct strength analysis guide. Based on the prediction result, 15 parametric groups of design waves are calculated for each loading condition to determine the global structure stress distribution under each load combination, and thus to complete the yield strength check. The key node region of intersection between deck machinery room and trunk deck are taken as the example to accomplish the local strength analysis with fine mesh and several design improvements are made to solve the problem of stress concentration. According to the two common typical operational loading conditions and the operational requirement of 40a fatigue life in the North Atlantic Ocean, the hotspot stress transfer functions of two typical refined locations are computed based on the ABS global FEM direct strength analysis guide. The fatigue accumulation damage and fatigue life are obtained through spectral analysis to complete the fatigue strength check. The global strength and fatigue analysis method can be used in the structural analysis of other ultra large ships. |
| Key words: large LNG carrier global FEM strength analysis fine mesh fatigue analysis |
