Calculations of plastic strain and resistivity increase in a composite conductor subjected to cyclic strain

Graphical calculations are presented for plastic strain per cycle and accumulated plastic strain in aluminum composite conductors subjected to cyclic strain at 4.2 K. The graphical model is based on a constant-strain-range experiment with monolithic pure aluminum. Calculations are derived from synthesized stress-strain hysteresis loops. The resistivity increase expected from force controlled cyclic stress is shown to be substantially less than that arising from constant strain range cycling. Suggestions are given for decreasing resistivity degradation in the composite conductors of cycled magnets