3-Dimensional Stress Analysis of an Insulation System for TGZ Membrane Type LNG Carriers

Abstract

The TGZ membrane system, which is one of the insulation systems used for the cubic tank type LNG carrier, is a layered structure of orthotropic materials and has a complex stress distribution owing to the discontinuities of geometry and material. Stress distributions obtained from 2-D FEM model usually employed in the structural design were compared with those from 3-D FEM model under typical load conditions. 2-D FEM model assuming plane strain condition was found to be mostly conservative and could be valid for design use.