独立液货舱支撑结构是该型船的重要构件,起到连接船体结构和液货舱/灌的作用,实现力的传递、变形的传递、热的传递等功能。本文基于当前常见的独立液货舱（单罐和双耳罐）支撑结构设计形式,分析热传递过程的作用和方式,研究环境条件的传热模拟（空气对流）,分别提出适用于独立液货舱支撑结构和甲板罐支撑结构的温度场分析方法,可作为液化天然气（LNG）运输船和LNG燃料动力船罐体支撑结构温度场分析的参考。

As global warming increases, human activities in the polar waters become more frequent, such as transportation, resources exploration and exploitation. When a polar ship navigates in the ice-infested seas, the hull is exposed to actions from different kinds of ice features directly. This may cause potential damage to the hull structure at some occasions. According to IACS PC rule, it is required that structural analysis of hull structure under the impact of ice load should be carried out. However, it doesn’t give detailed method on how to implement it. This paper aims to give a solution on the implementation of structural analysis under ice load. A procedure of structural analysis based on linear and nonlinear FE methods was developed by considering ice load, hull structure, and strength criteria. Ice load is calculated based on IACS PC rule for linear FE model while it is assumed as loading and unloading curve for nonlinear FE model. By applying ice load to the structure model, the maximum yield stress and buckling factor are calculated and compared to the allowable value according to IACS PC rule. The bow and mid-ship of a polar ship was used in the case study. The results show that the maximum calculated buckling factor would exceed rule requirement based on linear FE analysis at the position of tween deck. As a compensation to linear FE analysis, nonlinear FE method is applied for the further study by considering elastic-plastic material and non-linear ice load. As a conclusion, some proposals on how to analyze the structural strength under ice load are provided. The proposed method is useful and promising to perform the structural analysis efficiently at the initial design stage of polar ship.
© 2019 by the International Society of Offshore and Polar Engineers (ISOPE).

As offshore wind energy moves to cold regions, existence of floating ice sheet is taken as a key technological challenge for offshore wind turbine design. How to estimate dynamic ice loads exposed by wind turbine tower at the waterline remains a question. This paper aims to present a numerical model which considers non-simultaneous ice crushing failure acting on vertical structure of wind turbine tower. The ice crushing force acting at local structure nodes are calculated and summed up to derive global force. The boundary of ice sheet is updated at each time step. Validation of dynamic ice loads against model tests in the ice basin are performed. It seems that the proposed model could capture the main trend of ice-wind turbine tower interaction at the vertical slope and is helpful in assisting the initial design of wind turbine towers in cold waters.
© 2019 by the International Society of Offshore and Polar Engineers (ISOPE).