船用LNG储罐的疲劳强度分析研究

LNG储罐受到惯性力载荷的作用,其结构强度需要进行评估,但由于其几何形状及边界条件复杂,一直缺乏相应的评估体系。提出LNG储罐疲劳分析的一般方法,以某LNG储罐为例,进行了疲劳损伤的计算及校核分析,对单元选择、模型简化、约束定义、载荷施加等给出了指导性意见,并探讨了储罐的布置方向对疲劳损伤计算的影响,研究结果表明,储罐沿船舶纵向布置时对结构设计的要求较高,应尽量选择横向布置方式。

Research on fatigue strength analysis of marine LNG tanks

The LNG tank suffers from inertial force load, so its structural strength needs to be evaluated. But there has been a lack of corresponding evaluation system, because of its complex geometry and boundary conditions. The general method of fatigue analysis of LNG tank is proposed. Taking an LNG tank as an example, fatigue damage calculation and checking analysis is conducted. The guidance for unit selection, model simplification, constraint definition and load application is given. The effect on fatigue damage calculation of the tank caused by arrangement direction is studied. Research results show that the higher requirements on structure design of LNG tank are needed when it is arranged longitudinally on the ship. So if possible, the transverse arrangement is suggested.