Analysis of the lamination stack influence on the stiffness of stator active component



For electric motors light weight construction is becoming increasingly important. Therefore the mechanical behavior of the lamination stack is necessary to be known for the simulation. The stacking of a lot of sheets has a relevant influence onto the behavior of the whole motor, because of the significant contact characteristics between the sheets. Quasi-static tests are performed to identify this. In these tests an axial load, representing the packaging process, is applied onto the stacked sheets and thereafter a cyclic load is superposed. With these quasi-static tests elastic and plastic effects and a hysteretic behavior are detected. For modeling this stiffness behavior nonlinear springs and frictional elements, containing the Coulomb's law, are assembled. The nonlinearities and the hysteresis are dependent on the sheet's roughness. Moreover the behavior of the stack is influenced by the coreplate varnish viscoelasticity. With modeling these effects, the measured values can be well simulated. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)