Effects of Low Temperature and Water Saturation on the Blast Response of Carbon and E-Glass Epoxy Composites

A computational study has been conducted to investigate the coupled effect of low temperatures and water saturation on the dynamic response of carbon/epoxy and E-glass/epoxy composite plates subjected to air blast and near-field explosive loading conditions. The temperature range considered corresponds to room temperature (20 degrees C) down to arctic seawater and extreme ocean depth conditions (- 2 degrees C). Each material has been evaluated in both dry and fully saturated conditions, with material properties taken from prior detailed mechanical evaluation studies. For the air-blast modeling, the study examined the transient elastic and damage response with both simply supported and fully fixed boundary conditions. The underwater explosive/blast modeling utilized fully clamped air backed plates which were loaded with an RP-503 explosive submerged in water. Finally, an evaluation of the effects of temperature/saturation coupling on the fundamental natural frequencies of the clamped plates was conducted. The results of the complete study show that plate responses to the dynamic loading conditions are dependent upon both the temperature and the saturation state. For each loading condition, the peak deformations are larger for panels, which are saturated with water, as compared to those in a dry state. Furthermore, panels evaluated at lower temperatures generally had lower displacements as compared to room temperature conditions. The study has shown that when considering composite materials, which will be subjected to shock loading in low temperature or wetted conditions, the material properties play a significant role in the transient and damage responses.