Computation of deformation of ferromagnetic material

Several different methods for computing the magnetic force distribution can be found in the literature. In addition to magnetic forces, magnetostriction also contributes to deformation. Magnetic forces and magnetostriction are often treated and computed as different phenomena. A method for modelling magnetic forces and magnetostriction in ferromagnetic material is presented, in which magnetic forces, magnetostriction and deformation are considered simultaneously. This method is discussed with regard to the theoretical background. In particular, phenomena such as the so-called ´form effect in magnetostriction´, which clearly illustrates the presence of both magnetostriction and long-range magnetic forces, are treated. Further, the method is compared with other methods. It can be shown that for some particular expressions of the constitutive laws, the method corresponds to other methods found in the literature. Finally, the numerical implementation of the method to compute the magnetic field and deformation in ferromagnetic material using the finite element method is discussed.