Strain Distribution and Critical Current Characteristics of an Individual REBCO Tape and Quasi-Isotropic Superconducting Strand Under Bending Loads by the Layerwise Theory

In applications of the second generation (2G) REBCO tapes, in order to achieve high engineering current density and alleviate the anisotropy of critical current, many structures of superconducting strands/cables made of REBCO tapes were proposed. In this paper, to investigate the bending behaviors of an individual REBCO tape and the quasi-isotropic superconducting (Q-IS) strand, we firstly build a three-dimensional (3D) model by the Layerwise theory to analyze the strain distribution of an individual REBCO tape under different tension loads which gives us the stress-strain curve of the tape. Then the bending characteristics of an individual REBCO tape are investigated by experiment, calculation and simulation. In addition, critical current features of the Q-IS strand under bending loads are studied in the same way. Experimental, numerical and simulated results are in good agreement. The results indicate that the Q-IS strand possesses great electromechanical performance under bending loads and it can be applied in many fields such as power transmission, large-scale superconducting magnets and nuclear fusion.