An adaptive degrees-of-freedom finite element method for 3-D nonlinear magneto-thermal field analysis

An adaptive degrees-of-freedom finite element method (FEM) for 3-dimensional nonlinear magneto-thermal fields is proposed in this article. Both magnetic field and thermal field are discretized using a single FEM mesh, and their degrees of freedom (DoFs) are individually controlled based on the field characteristics. Before solving the algebraic equations, the constrained DoFs are removed using the slave-master technique. The computing time and the storage resources of the second set of FEM mesh are saved while meeting the different requirements on discretization. Data transfer between the thermal and magnetic fields are easily implemented, and mapping errors between different meshes are avoided. To showcase the feasibility and the effectiveness of this method, several numerical examples are tested.