Time-domain finite-element modeling of thin electromagnetic shells

In this paper, the authors propose a novel time-domain extension of the well-known frequency-domain thin-shell approach. The time-domain interface conditions at the shell surface are expressed in terms of the average (zero-order) instantaneous flux and current density vectors in the shell, as well as in terms of a limited number of higher-order components. The method is elaborated for a magnetic vector potential finite-element formulation. The validation is done by means of two 2-D test cases with pulsed magnetic field excitation. The results are in excellent agreement with those produced by a brute-force model in which the shell is meshed finely throughout its thickness.