Modeling of the bending strain dependence of the critical current in Bi2223/Ag composite tapes based on the damage stress of the superconducting filament

An analysis model of the bending strain dependence of the critical current in multifilamentary Bi2223/Ag composite tapes is presented. To investigate the effect of the mechanical properties of the Bi2223 superconducting filament, the actual part for carrying current, its damage stress and elastic modulus are introduced. The calculated result of the variation of the critical current with the bending strain is well agreed with the experimental one. The further studies find that the mechanical properties of the filament have a remarkable effect on the bending strain dependence of the critical current. Specifically, the larger the damage stress and elastic modulus of the filament are, the higher the critical current is, when the bending strain increases to a larger value beyond the critical one.

► An analysis model of the Ic–ε (bending) relation in Bi2223 composite tapes is presented. ► The model is on the ultimate strength σD and elastic modulus E of Bi2223 filaments. ► These σD and E, as mechanical essences of materials, can be experimentally obtained.