Development of Prediction Techniques for the Vibrational Characteristics of Laminated Steel Sheets Used in Permanent Magnet Motors

With the explosive increase in motor-driven products due to electrification, the issues related to motor noise and vibration (NVH) have become increasingly prominent. To prevent motor noise issues proactively, accurate prediction of noise characteristics during the design phase is crucial. However, the laminated steel sheets that constitute the stator exhibit highly anisotropic material properties, making it challenging to accurately understand their vibrational propagation characteristics. This paper presents a method for FEM modeling of laminated steel sheets through the application of contact analysis. The analytical model that converts the contact pressure between each steel sheet into contact stiffness successfully predicted the lower-order eigenvalues of the stator core within a 7% margin of error. By translating this model into anisotropic material properties and reducing the number of model elements, a reduction in analysis time was achieved, thereby establishing its usefulness as a model for preliminary noise analysis.