Magnetostriction and magnetic forces are a major cause of vibrations and noise of electromagnetic devices. The measurement of the magnetostriction can either be done by using a direct method, is one of the fundamental issues that will be treated in the proposed project. A second fundamental problem is the mathematical modeling of the irreversible behaviour (hysteresis) of ferromagnetic materials. The development of a new measurement method for magnetostriction is a third problem that will be treated in this project. In this project we will therefore make use of the heterodyne interferometer technique.