Identification of Magnetic Induced Strain of Electrical Steels Using Non-Destructive Acceleration Measurement and Inverse Vibration Modeling

Abstract Magnetic induced strain is an important source of vibration in electromagnetic components and electrical machines. This magneto-mechanical behavior is identified using a non-destructive experimental technique that consists in measuring in a Single Sheet Tester the time dependent acceleration at the free end of a fixed-free magnetic sheet and its corresponding magnetic field and induction signals. The determination of this property in the longitudinal direction is investigated using an inverse application of the longitudinal vibration equation. The strain dependence on the exciting frequency as function of the resonance frequency is also evaluated. The apparent strain that includes the inertia effect is distinguished from the magnetic-induced strain. Both strains are identified and analyzed for different frequencies lower and higher than the sample’s natural frequency. We also investigated the effect of excitation’s harmonics on the mechanical response.