Glass composite vibration isolating structure for the LNG cargo containment system

The primary barrier of the cargo containment system (CCS) for the liquefied natural gas (LNG) carriers is subjected to large impact loads due to the cavitation of LNG. Therefore, the impact loads should be reduced to protect the insulation foam from cracking because the foam has very low fracture toughness at the operating temperature of −163°C. In this study, a corrugated-plate type vibration isolating structure (VIS) has been developed using glass fiber reinforced composites to reduce the load transmissibility from the primary barrier to the insulation foam of the CCS at cryogenic temperature. The uniform spring constant characteristic was achieved by optimizing the stacking sequence of the composite laminate and the wavelength of the corrugation. The crack resistance of the VIS against the impact load was measured by the drop weight impact test with respect to the stacking sequence of the glass composite laminate. The specifications of the VIS were obtained by the finite element analysis and experiments. Also, the durability against repetitive impacts on the VIS was investigated.