Impact behavior of hollow glass bubble reinforced foam core LNG insulation panel in cryogenic temperature

Composite sandwich panels are applied to numerous structures owing to their excellent mechanical properties and thermal performance. In marine craft, sandwich panels are located on the inner walls as an insulation system for the liquefied natural gas (LNG) cargo containment systems (CCSs). Polyurethane foam (PUF), as an insulation material, is commonly used as the core material against a cryogenic temperature of –163°C for the LNG CCSs. Owing to its excellent thermal performance that prevents heat flow from the outside, and because LNG is transported at cryogenic temperatures, PUF is the preferred choice as a core material. However, the LNG CCS is subjected to fluid impact load due to sloshing during a laden voyage, and therefore, the core material needs to be reinforced. In this study, a reinforcement material made of hollow glass bubbles (HGBs) was added to PUF to help withstand the sloshing loads, and the performance of the specimens was investigated in terms of their impact strength and absorption energy. The mechanical impact strength of the final products was investigated through an impact test at cryogenic temperatures and the absorption energy was analyzed along with the dynamic compressive behavior of the sandwich panels.