Modelling of the Current-Voltage Characteristics of the HTc Superconducting Tapes Subjected to the Bending Strain Process

Abstract

In the paper the current-voltage characteristics of the HTc superconducting tapes subjected to the bending strain process have been analyzed. The variation of the strain acting on the superconducting element, a filament in the first generation (1G) or a film in the second generation (2G) composite tape, in respect of the applied bending strain, has been considered. The elasticity properties of tape and geometry of micro-cracks have been taken then into account. Decreasing with length along the tape solution of the equations describing current and voltage distribution in composite bent superconducting tape, with micro-cracks has been found and used for determining current-voltage characteristics. For description of these characteristics theoretical model in the case of the critical current determined by the flux creep effect and overall capturing of the vortices on the structural defects has been proposed. The model has been fitted to the experimental current-voltage characteristics of a Bi-based tape subjected to the bending strain. Fairly good agreement between experiment and theoretical calculations has been obtained.