LNG선 화물창 단열시스템의 수면낙하 내충격 응답해석

Abstract

While the safety assessment of cargo containment system(CCS) in membrane type LNG carriers has to be carried out in consideration of sloshing impact pressure, it is very difficult to figure out its dynamic response behavior due to its very complex structural arrangements/materials and complicated phenomena of sloshing impact loading. For the development of its original technique, it is necessary to understand the characteristics of dynamic response behavior of CCS structure under sloshing impact pressure.

In this study, for the exact understanding of dynamic response behavior of CCS structure in Mark III type LNG carriers under sloshing impact pressure, its wet drop impact response analyses were carried out by using Fluid-Structure Interaction(FSI) technique of LS-DYNA code. The wet drop impact response analyses were validated through a series of wet drop experiments for the enhancement of shock response analysis technique accuracy. It might be thought that the structural response behaviors of shock response analysis, such as impact pressure impulses and resulted strain histories, generally showed very good agreement with experimental ones very appropriately by using fluid-structure interaction analysis technique of LS-DYNA code, finite element modeling and nonlinear material properties of CCS structure, modeling and equation of state(EOS) of fluid domain. Through this study, the characteristics of structural shock response behavior of CCS structure could be also sufficiently figured out by careful examinations of the effects of specimen weight, drop height, incident angle and corrugation on the shock response behaviors.