Theory analysis of critical-current degeneration in bended superconducting tapes of multifilament composite Bi2223/Ag

• We proposed an empirical model to describe carrying-current degradation of bent Bi2223/Ag tapes.
• Asymmetric damage of superconductor multifilament is taken into account.
• Both the loading and unloading processes of bend deformation are captured.
• Carrying-current property can be improved by designing configuration of the multifilament core.

This paper proposed a degradation model to explore the influence of the mechanical bending deformation on the critical-current of superconducting composite Bi2223/Ag tape taking into account the asymmetric mechanical damage. With the aid of Weibull distribution function of statistical damage of filaments, the critical-current dependence upon bending strain of the superconducting tape in processes of loading and unloading is characterized. The degradation profile of critical-current in the superconducting composite tape is theoretically investigated by the proposed model for different critical damage strains and configurations of superconducting multifilament core at the cross-section. It is shown that the theoretical predictions are in reasonably good agreement with the experimental data, and the configuration of the multifilament core of the superconducting composite tape has a significant influence on the critical-current degradation. The superconducting multifilament core located near the compression region of the cross-section remarkably improves the mechanical and carrying-current capabilities of the superconducting composite tape.