Validation of vibration synthesis with lumped tooth forces for electric motor NVH prediction

In this paper, the vibration synthesis used for the prediction of the vibration behavior of a Permanent Magnet Synchronous Machine (PMSM) is developed with Lumped Tooth Forces (LTF) and validated against a reference model. On the one hand, the reference Finite Element (FE) method applies FE-calculated magnetic nodal forces onto a 3D FE structural model via dedicated mesh mapping. On the other hand, the vibration synthesis approach stores unitary vibration responses and uses them with decomposed forces to obtain the vibration response of the electric motor. To support the validation process, an intermediate step will also apply the LTF on the 3D FE structural model. It will be shown that the vibration synthesis offers the same accuracy as the standard FE approach, especially when used with LTF. However, the vibration responses will show discrepancies when compared with the complete set of nodal forces, which will highlight the importance of properly mapping the forces similarly in both methods.