Development of a simplified numerical model for the design of 2G high-temperature superconductors

Within the past few years robust superconductor known as Second-generation (2G) High Temperature Superconductor (HTS) were developed for different industrial applications. Their fabrication includes a phase of large bending, which induces both axial and shear stresses, which could lead to the degradation of the super-conductive substrate. The design of HTS requires analysis of the stress and strains induced during their fabrication. The use of the finite element method for the analysis of this complex material requires large meshes and computation time, because of the ultra-small thickness of the supra-conductive substrate. In this paper, we present a simplified model, which is based on the classical beam theory together with the discretization of each layer in small sub-layers working under purely axial stress. The model takes into consideration the plastic behaviour of the HTS constitutive materials. The model is validated by its confrontation to finite element analyses. Then it is used for the optimal design of HTS by the analysis of different industrial configurations. Analyses lead to some recommendations concerning the optimal configurations that reduce the stresses in the supra-conductive substrate.