Mechanical-Electromagnetic properties of high-temperature superconducting CORC-CICC Cables under axial tensile load

Abstract High-temperature superconducting (HTS) CORC-CICC cables combine the high currentcarrying capability of CORC cables with the superior mechanical strength of the cable-in-conduit conductor (CICC) configuration, rendering them promising candidates for next-generation highfield fusion magnets and large-scale superconducting facilities. Nevertheless, the mechanisms underlying electromagnetic performance degradation under axial tensile loading remain incompletely understood. Specifically, strain transfer in multi-pitch and multi-layer structures, as well as the interplay between mechanical loads and electromagnetic losses, requires systematic investigation. In this study, an analytical mechanical model and a three-dimensional coupled mechanical-electromagnetic numerical model are established for this conductor configuration. The mechanical response, critical current reduction, and magnetization loss characteristics under axial tensile loading are systematically investigated. The influence of several key structural parameters including twist pitch, helical orientation, and the number of tape layers, on the axial strain distribution, critical current, and magnetization loss is also investigated. The results indicate that adopting the same primary and secondary helical directions enhances the tensile load-bearing capacity of the cable. Within an appropriate parameter range, a larger primary twist pitch combined with a smaller secondary twist pitch can effectively delay performance degradation. The primary twist pitch is found to have a limited effect on magnetization loss, whereas reducing the secondary 2 twist pitch results in increased magnetization loss. Increasing the number of layers can mitigate the decline in critical current in the outer layers to some extent, but too many layers may exacerbate stress concentration at the contacts. These findings provide fundamental insights into the coupled mechanical-electromagnetic behavior of CORC-CICC cables from both analytical and numerical perspectives, elucidate the governing roles of critical structural parameters, and furnish practical guidance for conductor optimization and engineering design in high-field superconducting magnet applications.