Strength assessment procedure of LNG CCS under sloshing load based on the direct approach

초록

As the size of LNG carrier ship has been expanded, it is expected that the sloshing impact on the LNG CCS (cargo containment system) is getting higher at the low filling condition. The sloshing pressure and structural capacity of the LNG CCS is carefully investigated during the CCS design since the sloshing impact has many technical issues such as extremely low temperature, high impact pressure, non-linearity of the fluid motion and so on. At first, the strength assessment procedure suggested by shipping registers, shipyards and several research groups are compared and discussed. This study also suggests a strength assessment procedure of LNG CCS including the sloshing pressure of large scaled model test and numerical analysis, static and dynamic structural response of cargo containment. Numerical analysis and experimental approaches of sloshing motion and pressures are commonly discussed to assess the sloshing pressure. Thereafter static and dynamic structural responses of the membrane tank are investigated by finite element analysis. Three different levels of strength assessment procedures are discussed based. Copyright © 2011 by the International Society of Offshore and Polar Engineers (ISOPE).