LOW-TEMPERATURE INTERLAMINAR SHEAR-STRENGTH OF REACTOR IRRADIATED GLASS-FIBER-REINFORCED LAMINATES

Glass-fibre-reinforced plastics (GFRPs) are candidate insulating mater ials for superconducting magnet coils in future fusion reactors. There fore, the influence of radiation damage (gamma and fast neutrons) espe cially on the interlaminar shear behaviour of these materials has to b e investigated carefully. Different types of GFRP laminate (two-dimens ional E- or S-glass fibre reinforcements, epoxy or polyimide resins) h ave been irradiated at room temperature in the TRIGA reactor (Vienna, Austria) and at 5 K in the FRM Munich (Garching, Germany) up to a neut ron fluence of 5 x 10(22) m(-2) (E > 0.1 MeV) prior to short-beam-shea r (SBS) testing at 77 K. After low-temperature irradiation, half of th e samples were subjected to a warm-up cycle to room temperature before testing at 77 K. Results on the influence of different radiation sour ces, irradiation temperatures and annealing cycles as well as the boro n content of some laminates on the interlaminar shear strength (ILSS) are compared and discussed, together with microstructural observations made with a scanning electron microscope. (C) 1996 Elsevier Science L imited