Tooth Base Geometrical Variability Effect on the Vibration Behavior of the Stator

The magnetic pressure generated in the stator of electric machines can be a significant source of noise and vibration. The vibration behavior of the stator and such mechanical structures primarily depends on their geometry. Although the stator is often considered a simple structure, its teeth are not included in this assumption. In this paper, we endeavor to evaluate the impact of stator geometrical variability on the vibration behavior of electric machines. Our sensitivity study reveals that natural frequencies and frequency response functions are highly sensitive to geometrical variability. To account for this, we conducted a variability propagation study using a stochastic finite element model. Our findings show negligible variability on the natural frequencies but a high variability on the frequency response functions, even with low input variability. As anticipated, our study highlights the critical role of accounting for geometrical variability to enhance the accuracy of finite element models and strengthen their predictive power. However, the main contribution of this work is that the vibration behavior of the stator is not coupled, implying that the impact on natural frequencies does not necessarily reflect the same effect on the frequency response function.