Modeling analysis of the critical current of bent Bi2223 composite tape based on the damage strain parameter and the shape of the core

We present a new modeling approach to describe the relation between the critical current and the applied bending strain of a multifilamentary Bi2223/Ag/Ag alloy superconducting composite tape. In the model, the shape of the superconducting core, in which the Bi2223 filaments that transport the superconducting current are embedded in Ag, and the damage strain parameter, defined as the difference between the intrinsic tensile fracture strain and the residual strain of the filaments in the sample length direction (= current transport direction), are combined with the exerted strain distribution in the bent sample. The extent of the damage to the core and the corresponding critical current are expressed as a function of bending strain. The present approach describes well the measured critical current-bending strain relation for the three different fabrication-route samples