Mechanical behavior of HTS tapes in highly flexible REBCO cable under torsional and tensile loads

Abstract Different cables composed of high temperature superconducting (HTS) tapes (REBCO) have been developed for the generation of high magnetic fields and the transmission of large currents. Among HTS cables, CORC ® (Conductor on round core) cable has become a promising candidate structure. In order to improve the flexibility of CORC ® cable, a new kind of cable called HFRC (highly flexible REBCO cable) has been proposed, in which the configuration is similar to CORC ® cable. During the production of HFRC, REBCO tapes are wound on the surface of a spiral tube layer by layer. Compared with the solid core of traditional CORC ® cable, the spiral tube is more prone to complex deformation under external loads, which results in special characteristics of REBCO tapes. In this paper, we analyze the deformation processes of spiral tube under tension or torsion. Based on the geometrical relationship between the tapes and the cable core, the strain in REBCO tapes is predicted. The FEM models of HFRC/traditional CORC-like cable are built and verified by experiments. Throughout simulations, the variation of the strain and local creases of tapes with the design parameters of core is investigated. Relevant findings provide a reference for the structural optimization of HFRC.