  This paper presents a new time-domain finite-element approach for modelling
thin sheets with hyperbolic basis functions derived from the well-known
steady-state solution of the linear flux diffusion equation. The combination of
solutions at different operating frequencies permits the representation of the
time-evolution of field quantities in the magnetic field formulation. This
approach is here applied to solve a planar shielding problem in harmonic and
time-dependent simulations for materials with either linear or nonlinear
characteristics. Local and global quantities show good agreement with the
reference solutions obtained by the standard finite element method on a
complete and representative discretization of the region exposed to a
time-varying magnetic field.
