The effect of radiation and cyrogenic temperature on the fatigue resistance of G-11 glass-cloth/epoxy laminates

Tension-tension fatigue tests were performed on unirradiated and irradiated G-11 CR notched fatigue specimens at 295 and 77 K. Fatigue failure was based on the initiation and propagation of fatigue cracks from the notch roots to a selected length. Results indicate an increase in fatigue resistance at cryogenic temperature, a moderate ratiation effect at both test temperatures and substantially different failure modes at 295 and 77 K. (orig.)