Electromagnetic, Thermal, and Mechanical Modelling of Thin-Wall HTS Bulks During PFM

High-temperature superconductors, especially rare earth barium copper oxide (REBCO) bulks, are promising for superseding permanent magnets in power applications. However, being essentially ceramics, their practical use is limited by their brittleness that turns into mechanical failures during high-field magnetization. These failures often arise from defects that appear during the fabrication process, such as pores and cracks. This fragility may be mitigated by including artificial holes in the bulks. The number, size and distributions of these holes may not just improve cooling, but they may also reduce porosity, and enhance both mechanical strength and flux pinning. Modelling the impact of such holes on the trapping performance of the bulks and their thermo-mechanical response to magnetization, particularly the pulsed field magnetization (PFM) that is considered practical for actual applications, is challenging and requires a multiphysics approach. In that context, the present work introduces a 2D finite element model (FEM) that includes coupled electromagnetic, thermal and mechanical physics to simulate thin-wall REBCO bulks with ring reinforcement. The numerical results provide insight on how to maximize trapped magnetic fields while minimizing mechanical loads with thin-wall reinforced REBCO bulks.