Structure Analysis Of Membrane-Type LNG Containment Systems Subjected To Sloshing Loads

LNG is the abbreviation for Liquefied Nature Gas. Membrane-type LNG carrier is the special ship that transports LNG under low temperature of-163℃. With the rapid development of national economy in China, the demand of nature gas is steadily increasing. A great deal of liquefied nature gas will be imported in the near future because the current output can not meet the market demand. LNG carrier plays a very important role in world nature gas market due to the merit of good economy and flexibility in reserving and transporting liquefied nature gas. China has the ability to build LNG carriers through the introduction of cargo containment system (CCS) patent technology from GTT Company. However, it still needs to study further in order to achieve R&D independently. Therefore, it has practical significance to research in this domain.The development of LNG carriers is a process of continuously developing to large-scale. LNG carriers with membrane-type containment system have been operating at high filling conditions without significant damage for the last 40 years. Recently, the growing LNG market demands new LNG carriers with cargo capacity 50%-80% larger than the existing vessels. The size and shape of the tank change accordingly. The impact pressure due to liquid cargo motion has been regarded as one of the most important load factors when designing new cargo containment system for membrane-type LNG carriers.As the key technology of membrane-type LNG carriers, CCS has drawn wide attention since its inception. And many companies in the world spend a lot of financial power and material resources on R&D. Once the CCS structure were damaged, it would be not only difficult to repair but also costly. In case of an accident, it would bring great loss to lives and property of human being due to its particularity.This thesis aims to probe into ABS Guidance Notes on Strength Assessment of Membrane-Type LNG Containment Systems subjected to Sloshing Loads. LS-DYNA is used to simulate the 2D and 3D sloshing in different loading levels and different frequency. Then it is determined the most severe sloshing load and carries through static FE analysis, linear transient FE analysis and non-linear dynamic FE analysis to GTT No.96 containment system and compared the results.