Vibrational Model Updating of Electric Motor Stator for Vibration and Noise Prediction

In order to improve the comfort of passengers in electrical vehicles, it is increasingly important to consider the vibroacoustic behavior of electrical machines during the design phase. In this work, a weakly coupled multiphysical model for electrical machine vibration and noise prediction is presented and applied to a 75 kW railway traction motor. The main objectives of the model are to obtain firstly the vibrational level and secondly the acoustic pressure level predictions. The multiphysical model includes an electromagnetic 2D model, a 3D structural vibrational model and an acoustic model, all of them based on the finite element method. The work is focused on the validation of the modal analysis and vibrational models, using a bottom-up approach. Experimental modal analyses at different assembly stages are performed in order to update uncertain input parameters of the structural model at those levels. An anisotropic damping model is developed and updated in order to obtain adequate FRF amplitudes and the mean squared error (MSE) metric is employed to quantify the correlation between the experimental and numerical results. Finally, vibrational spectra under nominal operational conditions of the motor are used to demonstrate the adequacy of the vibrational model.