Analysis of glass fiber reinforced composites in Membrane-Type LNG cargo containment system for structural safety using experimentally defined mechanical properties

Glass fiber-reinforced composites have been used as a secondary barrier structure in LNG cargo containment systems (CCS) for their excellent strength and corrosion resistance. However, during LNG transport, the tanks experience periodic thermal and bending stress because of the cryogenic environment. These conditions degrade the mechanical properties of the composites in the CCS. In this study, finite element analysis was conducted using the mechanical properties of each composite. A quasi-static tensile test was carried out, and the coefficients of thermal expansion were used to obtain the mechanical properties. To verify the reliability of the numerical analysis, modeled structural unit specimens were manufactured, and 3-axis strain gauges were attached to measure thermal strain under cryogenic conditions. Validation of the strain between experiments and computation was performed, and the finite element analysis was conducted based on the observed mechanical properties and their reliability.