SM.ANL Vibration calculations based on internal analytic models

MANATEE software e-NVH Structural Models
Sub-module SM.ANL
Function Vibration calculations based on internal analytic models
Validation SM_STA_001 SM_STA_002 SM_STA_003 SM_STA_004
See also Link to other modules

Objectives

In early design phase, vibration and noise levels of a high number of e-motor topologies must be quickly compared, especially during electromagnetic design optimization. Structural mechanics FEA calculations are too long for this, so semi-analytic structural models of stators and rotors are useful. This semi-analytical structural module of MANATEE software allows to quickly estimate radial deflections of the outer structure (stator or rotor) based on equivalent models.

Summary

This module calculates the natural frequencies of the outer structure (rotor or stator) based on an equivalent cylindrical shell or disk depending on electric motor topology. Dynamic radial deflections under magnetic forces are obtained using dynamic amplification factors of static response. Winding or magnet mass is taken into account.

For EV HEV NVH traction applications with a relatively high number of teeth, analytic model gives excellent agreement with 3D FEA models.

Examples of structural modes of a cylindrical shell (numerical calculation)
Examples of structural modes of a cylindrical shell (numerical calculation)

Technical details

The model used in MANATEE is close from J.F. Gieras model [1], including both extensional modes (purely circumferential) and modes involving longitudinal deflections. Some fitting coefficients based on EOMYS experience on more than 100 electric motors are also included.

The limits of this model depend on the boundary conditions and geometry of the stator, especially the number of teeth and the relative tooth to yoke height. For small number of teeth and long teeth it is recommended to use MANATEE coupling with structural FEA software SM.NUM1.

Tutorials

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