Sloshing impact loads have been reported repeatedly throughout the lifetime of the ship. However, a study on the mechanical performance of polyurethane foam with repetitive impact load has not been conducted despite the necessity of evaluation. Therefore, in this study, the effect of repetitive impact loading on mechanical behavior of glass fiber reinforced polyurethane foam was investigated. To do this, a series of drop impact test was performed on glass fiber reinforced polyurethane foam which applied to LNG insulation panel. After the impact test, evaluation of mechanical behavior was conducted.
The glass fiber-reinforced polyurethane foam (RPUF) has excellent mechanical performance and thermal insulation performance due to the porous microstructure with glass fiber and has been applied to cryogenic environmental structure (Desai et al., 2000). The liquefied natural gas (LNG) cargo hold should be able to withstand the impact load, thermal load and hydrostatic pressure (Park et al., 2016a). Fig. 1 shows typical failure in polymer foam for insulation panel under the repetitive impact of low energy. Failure of LNG cargo hold even under not an extreme condition can lead to a great loss of property and human life. Therefore, structural integrity and failure prediction are very important.
A performance evaluation study was also conducted considering the operating environment of the LNG storage structure to predict the behavior and damage of polyurethane foam. Park et al. (2016b) analyzed the effect of temperature on the compressive behavior of various types of polymer foams used in cryogenic applications (Park et al., 2016b). Denay et al. (2013) analyzed the behavior of polyurethane foams under various loading conditions such as monotonous, repeated compressive and creep loading under cryogenic environment (Denay et al., 2013). The tensile, compressive and shear performance of polyurethane foam under high strain rate range using Hopkins bar were also performed (Pellegrino et al, 2015).