Equivalent sources methods for the numerical evaluation of magnetic force with extension to nonlinear materials

In this paper the equivalent sources methods, written in terms both of the actual and of the external field, are used for the computation of the total force in two-dimensional axisymmetric problems. A Finite Element modeling of the magnetizing currents as field sources is presented in order to improve the formulations using the external field. The numerical accuracy of all the proposed formulae is thoroughly checked on linear and nonlinear test examples