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The purpose of this paper is to analyse the surface vibrations of an induction machine due to force waves acting on the stator and rotor core. The focus lies on the investigation of the influence of force waves with axial variation and with higher spatial ordinal numbers on the surface vibration of an induction machine and thus its emitted noise.

Unit force waves with different spatial ordinal numbers and varying in axial direction are set up and applied on the stator and rotor teeth of a structural finite element model of an induction machine. Structural harmonic analyses with different frequencies are performed and the deformation of the machine is determined. After that, the root mean square of the normal component of the velocity on the surface of the machine's housing is determined and compared for the different force waves.

The influence of force waves with spatial ordinal numbers of higher order can have a significant influence on the structural vibration, especially if the spatial ordinal number is near the number of teeth. Furthermore, it is shown that the structure may react sensitively to axial variations of the forces, particularly near distinct structural resonances.

The presented investigations show relevant issues influencing the noise behaviour of electrical machines.

The purpose of this paper is to set up a comprehensive numerical approach to estimate the 3D structural vibration and noise radiation of an induction machine.

The rotating force waves, acting in the air gap of an induction machine and obtained by an electromagnetic finite element multi‐slice simulation, are applied to the 3D structural finite element model and a structural harmonic simulation is performed. The sound emission due to the vibration of the surface of the machine is computed with a 3D boundary element model.

The paper outlays problematic issues when setting up the numerical models, i.e. the structural finite element model. The material properties strongly affect the structural behaviour and therefore the radiated noise.

The 3D force distribution in the air gap and the resulting vibrations are computed. The structural behaviour, i.e. the different vibrational behaviour of stator and surface is discussed. The correlation of the structural vibrations and the noise radiation is investigated.

The purpose of this paper is to analyse the eigenforms and eigenfrequencies of stator core stack by experimental and numerical investigation. The influence of material parameters on the structural vibrations is carried out in order to describe the laminated structure of stator core stack with a homogeneous material model.

The finite element method is applied for a numerical modal analysis. Therefore, a homogeneous transversally isotropic material model is introduced and the influence of each material parameter on the dynamical behavior is investigated. These material parameters are stepwise adjusted to the results from the experimental modal analysis. The investigation includes results from different stator core stacks.

The influence of material on the modal parameters is shown. Furthermore, material parameters are carried out for stator core stacks, which describe the measured dynamical behaviour.

The presented investigations show a useable material model and corresponding parameters to the description of the laminated structure of stator core stacks.