Effects of Sub-Freezing Temperatures on Graphite/Epoxy Composite Materials

Abstract

Moisture in composite materials has been the subject of considerable interest in the past decade. Many studies have shown that moisture directly causes damage in graphite/epoxy composite materials. With the increasing use of such composites in various environments, an assessment of the effects of sub-freezing and/or cryogenic temperatures on composites containing moisture is needed. This article presents a summary of these effects and demonstrates that reductions in strength at low temperatures are not due to the formation of ice crystals, but instead are due to changes in the residual stresses caused by absorbed moisture.