Membrane containment system behavior in case of collision

Start Page
474
End Page
488
Citation
International Conference and Exhibition on Liquefied Natural Gas, LNG: 474-488 (2016-04)
Contribution to Conference
18th International Conference and Exhibition on Liquefied Natural Gas, LNG 2016 
In order to respond to the more stringent regulations of the Emission Control Areas (ECA), LNG as a fuel is today recognized as a valuable alternative to HFO. The membrane technologies developed by GTT have proved for decades their efficiency for large Liquefied Natural Gas (LNG) transportation and storage. In the immediate future, membrane technology should equip smaller tanks of the 'LNG as a fuel' ship chain such as LNG bunker ships / barges or LNG fueled ships. Since those ships will operate in frequented harbours or routes, the risk associated to ship collision has to be specifically addressed. In this paper, statistical results of a collision risk analysis are first discussed to evaluate what is the associated probability of a container ship suffering a collision during its lifetime. On one hand, Finite Element Analysis allows the calculation of the deformation of the ship structure during identified collision events. Numerical results are supported by an empirical approach based on energy dissipation. On the other hand, maximum allowable deformations of membrane systems are demonstrated by experiments and numerical calculations. A safety assessment based on the structural response of the containment system under inner hull deformation is explained and supported by experience at sea.