Space Radiation Effects on the Thermo-Mechanical Behavior of Graphite-Epoxy Composites

Abstract

This investigation of composite material properties utilized T300/934 graphite-epoxy that was subjected to 1.0 MeV electron radiation for a total dose of 1.0 x 1010 rads at a rate of 5.0 x 107 rads/hour, simulating a worst-case exposure equivalent to 30 years in space. Mechanical testing was performed on 4-ply unidirectional laminates over the temperature range of -250°F (116 K) to +250°F (394 K). In-plane elastic tensile and shear properties as well as strength were obtained ( E1, E2, v 12, G12, XT, YT, S). The results show that electron radiation degrades the epoxy matrix and produces products that volatilize at the temperatures considered. These degradation products plasticize the epoxy at elevated temperatures and embrittle it at low temperatures, thereby altering the mechanical properties of the composite.