Two types of magnetostriction effects are important in the study of noise and vibration in electrical machines. The first one is the dependence of dimension and elastic properties on magnetic property and the second is dependence of the magnetization characteristics on stress. The first one, usually referred as the direct effect and is described with butterfly magnetostriction curve λ(H), while the second, referred as the inverse effect, is expressed with magnetization curves at various stress levels. The effect of the inverse magnetostriction (IME) on stator iron deformation is studied by using the magnetoelastic coupled FE analysis. The procedure of including IME in the coupled FE analysis is proposed. The inclusion of IME in magnetic field equation reflects in the formation of the stiffness matrix. The permeability of each ferromagnetic element is considered as the function not only of the flux density but also the stress. The IME is taken into account in magnetic force calculation. The force formula based on the virtual work principle is proposed. Besides the reluctance forces, the force due to the IME is added to the excitation matrix of elastic field equations. The proposed idea is implemented on a PM synchronous motor. The stator deformations as well as the force acting on the stator iron with and without IME are compared.
