Modeling and experimental validation of superconductor tape rolling

Efficient, defect-free manufacturing of high-temperature superconducting (H TS) wires and tapes is critical to a variety of defense and electrical powe r applications. To contribute to the improvement of these manufacturing ope rations, an analytical and experimental study of the early stages of the mu ltipass rolling process for transforming HTS wires into tapes was conducted . The rolling process was simulated by a three-dimensional (3D) finite elem ent model that uses the Drucker-Prager Cap plasticity model to represent th e powder core and a Von-Mises plasticity model with isotropic hardening to represent the silver sheath, The predicted cross,sectional geometry of the tapes is compared with experiments. The results show that the tape cross-se ctional geometry and powder core sizes can be predicted accurately. Further alternate boundary conditions were found to have minimal effect on the pre dicted cross-sectional geometry for the range of reductions considered, eve n though the frictional shear stress distributions were significantly diffe rent.