Working nonlinear transient eddy current problems with time harmonic solutions

The classical approach to solving transient problems is a finite difference-based time-stepping procedure. A powerful alternative when motion is not involved is to use time harmonic solutions to build the transfer function of the system, appropriate for a spectrum of source excitations. This paper shows how nonlinear problems are approached with this method, and how the transfer function is derived using variable metrics and multivariate splines.