Fatigue behavior of an insulation system for the ITER magnets in the load and strain controlled mode

摘要

The application of glass-fiber reinforced plastics as insulation materials for fusion magnet coils (e.g. of ITER) requires a full mechanical material characterization under ITER relevant conditions. The tension-tension fatigue test is useful to simulate the pulsed tokamak operation of the ITER coils in the relevant range of 10~4-10~5 cycles. The fatigue process can be run under load or strain control, which may influence the material behavior under cyclic load conditions. Therefore, investigations were performed at 77 K using an industrial glass-fiber reinforced composite impregnated with epoxy resin. For both the load and the strain controlled mode, i?-values of 0.3 and 0.5 and a frequency of 10 Hz were chosen. The results are discussed with respect to the lifetime performance of ITER.